                    IN THE COURT OF APPEALS OF IOWA

                                   No. 16-1489
                            Filed December 19, 2018


STATE OF IOWA,
     Plaintiff-Appellee,

vs.

JOE ANTHONY LOPEZ,
     Defendant-Appellant.
________________________________________________________________


      Appeal from the Iowa District Court for Polk County, Jeanie K. Vaudt, Judge.



      Joe Lopez appeals his conviction for murder in the first degree.

AFFIRMED.



      Mark C. Smith, State Appellate Defender, and Martha J. Lucey, Assistant

Appellate Defender, for appellant.

      Thomas J. Miller, Attorney General, and Linda J. Hines, Assistant Attorney

General, for appellee.



      Heard by Tabor, P.J., and Mullins and Bower, JJ.
                                          2


TABOR, Presiding Judge.

       Joe Lopez appeals his conviction for first-degree murder following the death

of his girlfriend’s twenty-month-old child, R.A. Lopez claims six trial errors—two of

which focus on the phrase “to a reasonable degree of medical certainty” as used

by medical experts. First, Lopez alleges the expert testimony was insufficient to

prove he inflicted R.A.’s fatal injuries. Second, he contends trial counsel was

ineffective for not requesting a jury instruction defining reasonable degree of

medical certainty. Third, he alleges counsel was ineffective for not objecting to

prior-bad-acts evidence. Fourth, he argues the district court should have allowed

the jury to hear he was willing to take a polygraph. Fifth, Lopez insists the district

court should have excluded the medical examiner’s manner-of-death testimony.

And sixth, Lopez asserts the prosecutor improperly invoked the “product rule” in

closing argument.

       On the sufficiency claim, when viewed in the light most favorable to the

verdict, the evidence presented by the State’s experts—combined with other

circumstances—allowed the jury to find Lopez guilty beyond a reasonable doubt.

On the first ineffective-assistance claim, we find counsel had no duty to ask for a

novel instruction defining a reasonable degree of medical certainty. We preserve

the second claim, concerning prior bad acts, for further development in an action

for postconviction relief. We find no abuse of discretion in the district court’s

exclusion of Lopez’s willingness to take a polygraph test or admission of the

medical examiner’s opinion on R.A.’s manner of death. Finally, Lopez failed to

demonstrate he was prejudiced by the prosecutor’s statements in closing
                                         3


argument.     Finding no reversible error, we affirm the first-degree murder

conviction.

I.     Facts and Prior Proceedings

       In the fall of 2014, Lopez moved into the basement apartment of a house in

Clive with his girlfriend, Nisa. She lived there with her three children—ages eight,

four, and not quite two. R.A. was her youngest.

       R.A. had flu symptoms the week of Thanksgiving 2014. When the family

ate a turkey dinner on Thursday, November 27, the toddler “nibbled a little bit and

then she ended up throwing up.” Nisa recalled R.A. was “very quiet” on Friday and

fell asleep on the couch.

       According to Lopez, around 2:00 in the morning on Saturday, November 29,

he was asleep in Nisa’s bedroom when he heard R.A. crying. Lopez later told

detectives he picked up R.A. from the mattress where she was sleeping with her

brothers and took her to the kitchen. He said he gave her water and a piece of

leftover turkey. Lopez recounted leaving R.A. in her highchair while he went to the

bathroom, the door slightly ajar.

       Lopez said, while in the bathroom, he “heard a smack on the floor.”

According to his interview, he returned to the kitchen, where he saw R.A. lying on

the floor next to her highchair. Lopez said he saw a bump on R.A.’s head. Her

eyes were rolled back, and she was gasping for air. Lopez woke Nisa, telling her

they needed to rush R.A. to the hospital.

       Nisa recalled when Lopez woke her, R.A. already had her coat and boots

on and was not making any sounds, and Lopez looked worried. Nisa felt a bump
                                            4


on the back of R.A.’s head. Lopez drove Nisa and R.A. to the hospital. While on

the way to the hospital, Lopez told Nisa:

       R.A. woke up crying and that he went in the room and picked her up
       and took her to the kitchen and sat her down on her highchair and
       gave her a couple pieces of turkey, and he went to the restroom, and
       . . . right when he sat down he heard a bump.

       Upon arriving at the hospital, Lopez took R.A. inside while Nisa parked the

car. Lopez informed emergency room staff R.A. fell out of her highchair. R.A. was

non-responsive and struggling to breathe on her own. Emergency-room staff

intubated her and began assembling a team of physicians to treat her.

       As the on-call trauma surgeon, Dr. Richard Sidwell evaluated R.A. when

she arrived at the hospital. Dr. Sidwell described the back of her head as “boggy,

and that means swollen, squishy.” He further observed

       a skull fracture toward the back of her head, a skull fracture, and then
       within her skull, injury to the brain itself, so that’s hemorrhage around
       the brain and creating pressure on the brain. So we knew about her
       severe head injury.
               Also after evaluation, the initial evaluation, we knew that she
       had at least four rib fractures. She had fractures of ribs one and two
       on both sides. Those are the injuries, in addition to a bruise on her
       head and a scrape on her chin. Those are the injuries that we knew
       about after her evaluation in the emergency room.

After examining R.A., Dr. Sidwell spoke with Lopez and Nisa. Lopez repeated his

version of events, but Dr. Sidwell was skeptical.          During the State’s direct

examination, Dr. Sidwell opined, “[H]er injury situation is very suspicious for a

nonaccidental trauma, meaning she didn’t just accidentally fall out of a high chair.”

       Dr. Sidwell called in neurosurgeon John Piper to join R.A.’s trauma team

that morning. Dr. Piper also evaluated R.A. in the emergency room. His primary

concern centered on the fact R.A. “was in a very deep coma and was having
                                         5


problems breathing spontaneously.” R.A.’s trauma team ordered scans to identify

potential head injuries.

       According to Dr. Piper, the preliminary scans demonstrated

       evidence of hemorrhage around the surface of [R.A.’s] brain or in the
       spinal fluid spaces. None of those hemorrhages were large where
       we could go in and maybe help with the pressure. They were very
       thin little layers of blood, but there were many areas of hemorrhage
       that we could see.

       When asked by the prosecutor whether R.A.’s injuries were consistent with

falling from a highchair, Dr. Piper responded, “No, they were not.” He elaborated,

       [W]e see people all the time that fall out of high chairs or shopping
       carts, and of those people that we see, it’s probably far less than ten
       percent of them that actually have found to have an injury at all. And
       of the injuries that they do have, typically they’re very, you know,
       more mild. There are people who have maybe just a tiny little spot
       of blood or a small crack in the bone . . . . So her condition was way
       worse than the typical condition someone would have from a simple
       fall.

       Dr. Piper was even more alarmed after reviewing R.A.’s autopsy and

learning she suffered axonal tears:

       [A]xonal injury is different because axonal injury tells us that there
       have been forces that are different than just a simple fall. It implies
       that there’s either flexion, extension, and rotation that occurs to the
       head because those fibers—what “axonal” means is that the fibers
       called the axons of the nerve are sheared, so a certain number of
       them will be lost from that shearing motion. So it implies something
       much more than just a simple . . . fall.
              It is seen most commonly in patients literally that are thrown
       out of vehicles in an accident. So if someone is driving sixty miles
       an hour and they hit a structure and are thrown through the
       windshield and tumble and roll literally sixty to a hundred feet
       sometimes away from their vehicle, those people will oftentimes
       come in with the shear injury. So it’s usually associated with very
       severe injuries that involve a rapid back and forth movement or
       rotational movements. So it’s something you just don’t see from a
       fall.
                                             6


         When radiologist Bradley King reported for his shift the morning of

November 29, he found the overnight radiologist had already performed scans of

R.A.’s head and cervical spine. When reviewing those images, Dr. King noted

additional posterior medial rib fractures. Dr. King testified, “Posterior medial rib

fractures are considered to be a classic sign of child abuse.”

         The State asked the radiologist if he could delineate a timeline of the injuries

he saw through imaging. Dr. King said he assumed fractures were acute1 unless

otherwise noted, “which means if I had seen a fracture that was in a state of healing

or I felt that the fracture was old, then I would have noted that in my report.”

Because he saw no signs of healing, he opined the rib fractures occurred within

“probably a week or less.”

         Pediatrician Kenneth McCann examined R.A. in the afternoon on November

29. Dr. McCann, a child abuse specialist, also reviewed R.A.’s chart and spoke

with Nisa. After his consultation, Dr. McCann concluded R.A.’s injuries were

inconsistent with falling from a high chair.

         Attending R.A’s autopsy provided Dr. McCann additional insight.            The

autopsy revealed mesentery bruising. Dr. McCann testified, “[R.A.] had two C-

shaped bruises on her abdomen. And we know abdominal bruising is a high red

flag for bruising deeper down. So that sort of puts two-and-two together in my

head.”

         Dr. McCann testified regarding the timing of R.A.’s injuries. He described

the skull fracture as “acute, immediately symptomatic. The minute that happened



1
    Dr. King described “acute” as meaning “the injury happened recently.”
                                                7


she would be unconscious.” He also confirmed R.A. had “fresh rib fractures.” But

Dr. McCann did not “feel comfortable” saying “the ribs had to have happened at

the same time as the skull fracture.”

          Later in the week, radiologist Brent Steinberg joined R.A.’s trauma team.

Acting as a fresh set of eyes, Dr. Steinberg reviewed R.A.’s images. Like the two

other radiologists, Dr. Steinberg believed R.A.’s injuries were caused by “potential

nonaccidental trauma.” In reaching that opinion, he considered (1) the complexity

of the skull fractures, (2) the quantity of blood between the brain and skull bone,

and (3) the number of rib fractures. To him, the rib fractures were the most telling

injury because of the significant force necessary to break the first and second ribs.

He also noted the fractures were equidistant from the spine, which “is unusual to

have in anything other than nonaccidental trauma.” According to Dr. Steinberg,

the mechanism usually causing this type of rib fracture is “an excessive hard

squeeze.”

          In the days after R.A.’s hospital admission, the doctors tried to keep her

stable but soon realized her brain swelling was “bad enough that it would be a fatal

situation without a drastic intervention.”             That drastic intervention was a

decompressive craniotomy.2 But the procedure was ultimately unsuccessful. On

December 3, 2014, R.A. succumbed to her head injuries.



2
    Dr. Piper described a decompressive craniotomy as
          trying to give the brain more room to swell. . . . We will go in and make a
          skin incision and we will take out the bone, so in her situation it would be
          left-sided. We would take out a large section of the bone and we will
          actually freeze that bone so we can put it in later on.
                   But what we’re able to do then is we’re able to sew in a very large
          patch of basically material that’s much like the covering of the brain, and it
          will allow the swelling to swell outward and the skin will be able to
                                          8


       Two days later, Polk County Medical Examiner Gregory Schmunk

performed R.A.’s autopsy. He described R.A.’s mesentery injury as “not more than

several days, maybe out five to seven days, old.” He concluded, “[F]alling from a

highchair onto your back—the history was that she was found on her back facing

up—would not cause this type of an injury.” Dr. Schmunk estimated the rib

fractures were less than one week old at the time of the autopsy. Dr. Schmunk

attributed the injuries to “an abusive act, a physical squeezing of the chest by

another person, certainly an adult.” Dr. Schmunk certified the cause of R.A.’s

death as craniocerebral trauma—in other words, “injury to the brain and skull.” Dr.

Schmunk testified “within a reasonable degree of medical certainty” he determined

the manner of death was “homicide or the act of another person on her.”

       In January 2015, the State charged Lopez with first-degree murder and child

endangerment resulting in death. His first jury trial ended in a mistrial. After the

second trial, the jury returned guilty verdicts on both counts. The district court

entered judgment for first-degree murder, sentencing Lopez to life imprisonment.3

Lopez appeals.

II.    Scope and Standards of Review

       We review challenges to the sufficiency of the evidence for correction of

errors at law. State v. Schlitter, 881 N.W.2d 380, 388 (Iowa 2016) (citing State v.

Neiderbach, 837 N.W.2d 180, 190 (Iowa 2013)). We review evidentiary rulings for




        accommodate that because it can stretch . . . . And then later on if someone
        is able to survive that, then we can put the bone flap back on.
3
  Under the one-homicide rule, the district court withheld judgment and sentence on the
conviction for child endangerment resulting in death. See State v. Fix, 830 N.W.2d 744,
749 (Iowa Ct. App. 2013).
                                            9

an abuse of discretion. State v. Tyler, 867 N.W.2d 136, 152 (Iowa 2015) (citing

State v. Elliot, 806 N.W.2d 660, 667 (Iowa 2011)). Likewise, we review the district

court’s ruling on Lopez’s objection to the prosecutor’s closing argument for an

abuse of discretion.4 See Coleman, 907 N.W.2d at 134. We review of ineffective-

assistance-of-counsel claims de novo. Schlitter, 881 N.W.2d at 388 (citing State

v. Tompkins, 859 N.W.2d 631, 636 (Iowa 2015)).

III.   Analysis

       A. To A Reasonable Degree of Medical Certainty

       R.A.’s cause of death emerged as the fighting issue at Lopez’s trial. To

prove causation, the State called six doctors. The defense answered with two of

its own medical experts. Of the eight total doctors, seven testified they were giving

their opinion “to a reasonable degree of medical certainty.” Four of those seven

witnesses offered a definition of “a reasonable degree of medical certainty.” 5




4
  Lopez argues prosecutorial error is a constitutional claim subject to de novo review. He
urges the supreme court to clarify the standard of review. Our supreme court has
repeatedly reviewed claims of prosecutorial misconduct for an abuse of discretion, except
in the ineffective-assistance context. Compare State v. Coleman, 907 N.W.2d 124, 134
(Iowa 2018), Neiderbach, 837 N.W.2d at 190, and State v. Krogmann, 804 N.W.2d 518,
523 (Iowa 2011) with Schlitter, 881 N.W.2d at 388. Accordingly, we do the same.
5
  (1) Dr. McCann testified:
        When I look at a case and come to an opinion that another physician of
        similar education, similar background, similar training, similar experience
        looking at the same case would come to a similar opinion as mine. There
        may not be 100 percent agreement on every detail, but overall they come
        to the same opinion as I would.
(2) Dr. Steinberg testified: “[N]othing is 100 percent or completely black and white in
medicine. . . . So you would show what somebody with your similar training and
background would come to the same conclusion, I think, is what I would probably say
would be good medical certainty.”
(3) Dr. Thomas Carlstrom testified for the defense: “In civil cases it’s greater than 50
percent” and he believed reasonable degree of medical certainty had no bearing in
criminal cases. “As far as I know—this is what I’ve always been told in my testifying—
greater than 50 percent.”
                                             10


       As mentioned in our opening paragraph, this phrase is central to two of

Lopez’s appellate issues: (1) the sufficiency of the evidence and (2) trial counsel’s

failure to request a jury instruction. Before addressing those issues, we briefly

explore the legal concept of “a reasonable degree of medical certainty.”

       In our legal lexicon, it means “[a] standard requiring a showing that the injury

is more likely than not caused by a particular stimulus, based on the general

consensus of recognized medical thought.”              Reasonable Medical Certainty,

Black’s Law Dictionary (10th ed. 2014). But legal scholarship has documented the

lack of an “agreed-upon meaning” for the phrase “reasonable degree of medical

certainty.” See, e.g., Lucy Johnston-Walsh et. al., The Unreasonably Uncertain

Risks of "Reasonable Medical Certainty" in Child Abuse Cases: Mechanisms for

Risk Reduction, 66 Drake L. Rev. 253, 255 (2018) (“[T]here is a range of meanings

attributed to this phrase by attorneys, judges, and testifying witnesses, is a high

risk of expert testimony being misinterpreted with potential false convictions or

improper exonerations in child abuse cases.”).

       In some jurisdictions, courts have struggled with the evidentiary standard

for the admissibility of medical testimony. See, e.g., Dallas v. Burlington Northern,

Inc., 689 P.2d 273, 277 (Mont. 1984) (“Although we still formally adhere to a



(4) Dr. Bradley Randall also testified for the defense: “My definition of ‘reasonable medical
certainty’ is a level of certainty a physician needs to make a diagnosis.” He said the level
of certainty necessary
        depends on the circumstance. If you go into the doctor with a sore throat
        and they say, “Gee, this looks like strep throat, I’m going to give you an
        antibiotic and send you home,” if they’re wrong, the consequences aren’t
        terribly high. So their level of certainty doesn’t have to be extremely high.
                 On the other hand, if the doctor says, “Gee, I think you have lung
        cancer, we’re going to take your lung out,” that physician better be very,
        very certain before they take your lung out.
                                              11


‘reasonable medical certainty’ standard, the term is not well understood by the

medical profession. Little, if anything, is ‘certain’ in science. The term was adopted

in law to assure that testimony received by the fact finder was not merely

conjectural but rather was sufficiently probative to be reliable. We are striving for,

what in fact, is a probability rather than a possibility.”), superseded by statute, 2011

Mont. Laws 618, as recognized in Ford v. Sentry Cas. Co., 282 P.3d 687 (Mont.

2012); Bara v. Clarksville Mem’l Health Sys., Inc., 104 S.W.3d 1, 5 n.1 (Tenn. Ct.

App. 2002) (decrying use of “magic words”). Other jurisdictions have embraced

the meaning of the phrase. See, e.g., Clifford v. United States, 532 A.2d 628, 640

(D.C. 1987) (“This standard of ‘reasonable’ medical certainty, reflects an

objectively well founded conviction that the likelihood of one cause is greater than

any other; it does not mean the expert is ‘personally certain’ of the cause, or that

the cause is discernible to a certainty.” (internal citation omitted)).

       In Iowa case law, we have “no requirement that the expert be able to

express an opinion with absolute certainty. A lack of absolute certainty goes to the

weight of the expert’s testimony, not to its admissibility.” Tyler, 867 N.W.2d at 153

(quoting Johnson v. Knoxville Cmty. Sch. Dist., 570 N.W.2d 633, 637 (Iowa 1997)).

To be considered by a jury contemplating the cause of death, witnesses need only

entertain a “reasonable degree of medical certainty” for their opinions. 6 Id. The

trial court must first act as the gatekeeper in deciding if the expert evidence is




6
  In Hansen v. Central Iowa Hospital Corp., the court clarified “[t]he rule is that expert
testimony indicating probability or likelihood of a causal connection is sufficient to generate
a question on causation . . . . Buzzwords like ‘reasonable degree of medical certainty’ are
therefore not necessary to generate a jury question on causation.” 686 N.W.2d 476, 485
(Iowa 2004).
                                           12

legally sufficient to warrant finding a causal connection. Id. Then the jury steps in

to decide if the causation evidence is persuasive beyond a reasonable doubt. Id.

       The requirement that the State prove all elements of a crime beyond a

reasonable doubt is “qualitatively different” in its application than the evidentiary

measure of medical causation. See State v. Webb, 309 N.W.2d 404, 413–14 (Iowa

1981) (quoting Commonwealth v. Stoltzfuz, 337 A.2d 873, 879 (Pa. 1975)). In

Webb, three doctors testified as to the cause of the victim’s death, stating their

opinions were based upon a reasonable degree of medical certainty. Id. at 413.

Webb objected, asserting the required standard for such testimony in a criminal

case should be proof beyond a reasonable doubt. Id. The supreme court rejected

Webb’s assertion. Id. at 414.

       With these principles in mind, we turn to Lopez’s sufficiency argument.

       B. Sufficiency of the Evidence

       Lopez contends the State failed to offer sufficient proof to convict him of

first-degree murder. Particularly, he calls into question the medical evidence. In

his view, “[w]ithout sufficient proof that the injuries were inflicted by Lopez, the jury

was only left to speculate what caused RA’s death.”

       To convict Lopez of first-degree murder, the State had to prove:

              1. On or about November 29, 2014, the defendant struck,
       slammed, squeezed and/or shook [R.A.].
              2. [R.A.] died as a result of being struck, slammed, squeezed
       and/or shook.
              3. The defendant acted with malice aforethought.
              4. Either
                     (a) The defendant acted willfully, deliberately and
              premeditatedly and with the specific intent to kill [R.A.];
                     OR
                                             13


                     (b) [R.A.] was a child and, under circumstances
               manifesting an extreme indifference to human life, the
               defendant either:
                            1. Assaulted [R.A.] as defined in Instruction No.
                     22. 7

                            OR
                            2. Committed child endangerment against
                     [R.A.] as defined in Instruction No. 23.8

Lopez asserts the State did not satisfy any of the elements because R.A. received

her injuries in an accidental fall.

       In reviewing a challenge to the sufficiency of the evidence supporting a

guilty verdict, we consider all evidence in the record, including all reasonable

inferences that may be fairly drawn from the evidence. Neiderbach, 837 N.W.2d

at 216. When we find substantial evidence in the record to support the jury’s

verdict, we uphold it.      Id. (citing Sanford, 814 N.W.2d at 615).           Evidence is

substantial if, “when viewed in the light most favorable to the State, it can convince

a rational jury that the defendant is guilty beyond a reasonable doubt.” Id. (quoting

Sanford, 814 N.W.2d at 615). The jury is free to reject and credit evidence as it

finds appropriate. Id.




7
  Instruction number 22 provided:
        An “Assault” is committed when a person does an act which is intended to
        either cause pain or injury to another person; or result in physical contact
        which will be insulting or offensive to another person; or place another
        person in fear of immediate physical contact which will be painful, injurious,
        insulting or offensive to the other person, when coupled with apparent
        ability to do the act.
8
  Instruction number 23 read:
        A person commits “Child Endangerment” when the person was a person
        having custody or control over the child or was a person who was a member
        of the same household where the child resided, by an intentional act or
        series of intentional acts, uses reasonable force, torture or cruelty, which
        results in bodily injury or that is intended to cause serious injury.
                                            14


       Lopez insists the State’s proof fell short because its experts reached their

opinions R.A.’s injuries resulted from abuse only “to a reasonable degree of

medical certainty.” He maintains medical certainty means “more likely than not,”

citing Black’s Law Dictionary, and “more likely than not” cannot satisfy the State’s

burden of proving the allegations beyond a reasonable doubt. 9 But our supreme

court rejected a similar cause-of-death argument in Webb, 309 N.W.2d at 413–14.

And we do the same here.

       Lopez contends his case is distinct because the State relied solely upon

expert testimony to prove he inflicted the injuries. Even assuming expert testimony

grounded in a reasonable degree of medical certainty would alone be insufficient

to convict, the State offered more than the medical evidence to incriminate Lopez.

For instance, the State provided testimony from investigators Lopez, by his own

admission, was the only adult caring for R.A. when she suffered her head injury.

And Nisa testified when Lopez woke her to say they needed to rush R.A. to the




9
  In his appellant’s brief, Lopez also alleges a weakness in the prosecution because the
State’s medical experts based their opinions on anecdata and literature. He alleges these
sources form impermissible bases for expert testimony in light of the evolving nature of
medicine and the possibility that “[r]easonable doctors may differ over various analyses of
findings.” But Lopez cites no law in support of his contention expert testimony based on
respected literature and experience in the field cannot support a jury’s finding of guilt
beyond a reasonable doubt. In fact, Iowa Rule of Evidence 5.703 provides:
        An expert may base an opinion on facts and data in the case that the expert
        has been made aware of or personally observed. If experts in the particular
        field would reasonably rely on those kinds of facts or data in forming an
        opinion on the subject, they need not be admissible for the opinion to be
        admitted.
Further, Lopez does not challenge the admissibility of the expert testimony on these
grounds. See generally 7 Laurie Kratky Dore, Iowa Practice Series: Evidence § 5.702:3
(Nov. 2018 Update) (explaining for their testimony to be admissible, expert witnesses must
have “adequate ‘knowledge, skill, experience, training, or education’” forming the basis for
his or her opinion on the subject matter). Accordingly, this sufficiency-of-the-evidence
argument fails.
                                            15


hospital, he had already fully dressed the toddler in her winter coat and boots.

Lopez controlled the narrative from there on, telling Nisa while they drove to the

hospital that R.A. fell from her high chair. Once at the hospital, Lopez directed

Nisa to park the car while he took R.A. inside to explain the situation to emergency-

room staff.

       On the issue of intent and motive, the State presented testimony from Nisa’s

landlady, who lived upstairs. The landlady recalled overhearing Lopez yell at the

children to “shut the fuck up” in the early morning hours several times in the fall of

2014.10 After Lopez grew angry during an argument over Nisa’s rent in early

November 2014, the landlady told Lopez he was no longer welcome to live in the

basement. Afterward, Lopez would sneak into Nisa’s apartment. The prosecutor

summed up the situation in closing argment: “He’s sneaking in and out of the

window now. So you have to consider how would you handle your stress if you

can’t yell at the kids anymore?”

       All in all, the State’s case did not rely solely on expert testimony. Admittedly,

the experts did not speak with one voice. Defense expert Dr. Carlstrom disagreed

with the State’s experts who opined R.A.’s injuries could not have resulted from a

high chair fall. But the jury found the State’s experts more credible, as juries are

entitled to do in a “battle-of-the-experts case.” See State v. Jacobs, 607 N.W.2d

679, 685 (Iowa 2000) (“The . . . trier of fact is not obligated to accept opinion




10
    Although we preserve a claim of ineffective assistance of counsel involving this
evidence, we may consider it when evaluating the sufficiency of the evidence. See State
v. Dullard, 668 N.W.2d 585, 597 (Iowa 2003) (“In determining whether retrial is permissible
all the evidence admitted during the trial, including erroneously admitted evidence, must
be considered.”).
                                             16


evidence, even from experts, as conclusive. When a case evolves into a battle of

experts, we, as the reviewing court, readily defer to the [fact finder]’s judgment as

it is in a better position to weigh the credibility of the witnesses.”).

          The State experts testified—and the defense experts agreed—R.A.’s brain

injury would have been immediately symptomatic. Lopez admits R.A. was in his

exclusive care when she sustained the skull fracture. The State presented five

experts who testified, based upon their knowledge and experience, R.A.’s brain

injuries were inconsistent with an accidental fall from a highchair. The experts

further opined the nature of R.A.’s rib and mesentery injuries bolstered their

conclusions. Considering the entire record, the jury’s verdict was supported by

substantial evidence. See Neiderbach, 837 N.W.2d at 212 (“Although none of the

State’s physician witnesses were willing to rule out the possibility that E.N.’s arm

had been broken in the manner Jonas described, they all agreed that his version

was highly unlikely.”).

          C. Ineffective Assistance of Counsel

          We turn next to Lopez’s complaints about his trial attorney’s performance,

starting with his allegation counsel should have requested a jury instruction

defining a reasonable degree of medical certainty.

          We apply the familiar Strickland11 standard for ineffective assistance claims.

Lopez must show by a preponderance of the evidence (1) counsel failed to perform

an essential duty and (2) prejudice resulted. See Coleman, 907 N.W.2d at 141.

We don’t always need to address both elements—failure to prove either prong


11
     Strickland v. Washington, 466 U.S. 668, 689 (1984)).
                                         17

defeats a claim. Id. (citing Nguyen v. State, 878 N.W.2d 744, 754 (Iowa 2016)).

Counsel breaches an essential duty by performing “below the standard of a

reasonably competent attorney.” Id. (quoting Ledezma v. State, 626 N.W.2d 134,

142 (Iowa 2006)). Recognizing the challenge in devising a trial strategy, we afford

attorneys a strong presumption that their “conduct falls within the wide range of

reasonable professional assistance[.]” Id. (quoting Nguyen, 878 N.W.2d at 752).

“Failure to raise a meritless issue does not establish counsel’s performance was

deficient.” Krogmann v. State, 914 N.W.2d at 307 (Iowa 2018) (citing State v.

Harris, 891 N.W.2d 182, 186 (Iowa 2017)).

       We preserve ineffective-assistance claims for postconviction relief unless

the record is adequately developed for resolution on direct appeal. State v. Clay,

824 N.W.2d 488, 500 (Iowa 2012).

       1. Instruction on Reasonable Degree of Medical Certainty

       Lopez contends his trial counsel should have asked for a jury instruction

defining reasonable degree of medical certainty. As chronicled above, several

expert witnesses used the phrase when describing the level of certainty backing

their causation opinions. While three expert witnesses used the term without

defining it, four experts did venture to explain the term during their testimony.

       On appeal, Lopez argues the phrase required a legal definition.              He

contends the expert opinions were “meaningless without an understanding of the

level of certainty to which each was held.” Lopez insists, “It was also important for

the jury to have an understanding of the difference between the level of proof for

the doctors’ opinions compared to the level of proof required for a guilty verdict.”

He urges trial counsel had an essential duty to request a definitional instruction.
                                              18

Because no uniform instruction exists, he suggests the Black’s Law Dictionary

definition quoted above.

         Lopez asserts counsel’s omission resulted in prejudice because the jurors

were unable to properly weigh the expert testimony considering they “did not know

whether the opinions rose to a level above speculation and suspicion.”

         Although we find it troubling the experts provided varying definitions of the

term when their testimony was fundamental to the case, the propriety of their

usage is not before us. Instead, we examine trial counsel’s duty to request a novel

jury instruction.12

         Trial courts are obliged to “instruct the jury as to the law applicable to all

material issues in the case.” See Iowa R. Civ. P. 1.924; see also Iowa R. Crim. P.

2.19(5)(f) (“The rules relating to the instruction of juries in civil cases shall apply to

the trial of criminal cases.”). In the context of ineffective assistance, attorneys may

satisfy the standard of normal competency even if they do not insist the trial court

give every instruction to which their clients are entitled. See State v. Broughton,

450 N.W.2d 874, 876 (Iowa 1990).               When deciding if counsel breached an

essential duty by failing to offer a particular instruction, we must look to the theory

of defense employed in the case. See State v. Virgil, 895 N.W.2d 873, 879 (Iowa

2017).




12
   The lack of a uniform instruction on this issue supports our ultimate conclusion. See
State v. Ambrose, 861 N.W.2d 550, 563 (Iowa 2015) (”Normally, we are slow to disapprove
of the uniform jury instructions.”). In addition, we do not expect trial counsel to be a “crystal
gazer” who can predict future changes in established law. See State v. Schoelerman, 315
N.W.2d 67, 72 (Iowa 1982).
                                          19


       Lopez’s trial strategy was to dispute the opinion of the State’s experts on

cause of death. But we are not convinced the definitional instruction he proposes

on appeal would have advanced that defense theory.

       The district court assembled a comprehensive set of instructions which

provided the jurors the law governing the material issues in the case. Particularly

on cause of death, the court instructed the jury the State had to prove R.A. died

“as a result of being struck, slammed, squeezed and/or shook” by Lopez. And the

court made clear that the State had the burden to prove the causation element

(and all other elements of the crimes) “by evidence beyond a reasonable doubt”

before returning a guilty verdict. The court also instructed the jury on the definition

of reasonable doubt. As for the medical causation evidence, the court instructed

the jury to “[c]onsider expert testimony just like any other testimony.” Under that

instruction, the jurors could give the expert testimony as much weight as they

thought it deserved, considering the expert’s education, experience, and his or her

reasons given for the opinion.

       What Lopez now claims was missing from those instructions was a

definition of medical certainty as “more likely than not.”          Lopez’s proposal

embodies a correct principle of law—but one outside the purview of the jury. The

“reasonable certainty” or probability of the expert’s opinion on causation is the test

for admissibility of that testimony. See Tyler, 867 N.W.2d at 153; see also Ranes

v. Adams Labs., Inc., 778 N.W.2d 677, 686 (Iowa 2010) (“Although it is the

province of the jury to evaluate the credibility of expert witnesses, trial courts have

a well-recognized role as guardians of the integrity of expert evidence offered at

trials.”). Once the court finds the expert testimony sufficiently certain for a party to
                                             20


present to the jury, the jury’s task is to decide if the State proved causation beyond

a reasonable doubt. See Tyler, 867 N.W.2d at 153. The jury did not need

information to retrace the admissibility determination.13 See generally State v.

Hamann, 285 N.W.2d 180, 186 (Iowa 1979) (rejecting consequence-of-not-guilty-

by-reason-of-insanity instruction because “such information is irrelevant to the

jury’s proper function”). Counsel’s failure to request an instruction defining medical

certainty did not amount to a breach of duty.

       2. Prior Bad Acts

       Lopez next argues trial counsel was ineffective for failing to object to the

landlady’s testimony about his early-morning yelling as prior bad acts. See Iowa

R. Evid. 5.404(b). The landlady testified about one particular incident when noises

coming from the basement apartment woke her from sleep. She recalled around

“3:00 or 4:00 in the morning,” she heard “children crying, TV, radio, and [Lopez]

was yelling” profanities at the children. She subsequently told the couple Lopez

was no longer welcome to stay in the basement apartment.

       The State believes the landlady’s testimony had a proper purpose—to prove

Lopez’s motive or lack of accident. See State v. Nelson, 791 N.W.2d 414, 425


13
   The Tennessee Court of Appeals came to a similar conclusion. In Miller v. Choo Choo
Partners, L.P., the plaintiff sued the defendant for injuries sustained after a slip and fall.
73 S.W.3d 897, 900 (Tenn. Ct. App. 2001). When the defendant requested a jury
instruction about causation, the trial court declined. The court of appeals held
                 The defendant’s proposed instruction regarding the requirement
        that expert testimony on causation be “reasonably certain” embodies a
        correct principle of law. However, we do not find that it was error not to
        instruct the jury as to this principle. That an expert’s testimony is
        “reasonably certain” is said to be a prerequisite to the admissibility of that
        testimony. The admissibility of expert testimony is a matter of law for the
        court, not the jury. The trial court did not err in refusing to give this
        instruction.
Id. at 909 (citations omitted).
                                         21


(Iowa 2010) (approving admission of other bad acts evidence “if there is a

noncharacter theory of relevance and the evidence is material to a legitimate issue

other than the defendant’s general criminal disposition”).

       Iowa Rule of Evidence 5.404(b) prohibits the use of “evidence of a crime,

wrong, or other bad act . . . to prove a person’s character in order to show that on

a particular occasion the person acted in accordance with the character.” The

supreme court has articulated a three-step analysis to determine admissibility:

       (1) [T]he evidence must be relevant and material to a legitimate issue
       in the case other than a general propensity to commit wrongful acts;
       (2) there must be clear proof the individual against whom the
       evidence is offered committed the bad act or crime; and (3) if the first
       two prongs are satisfied, the court must then decide if [the
       evidence’s] probative value is substantially outweighed by the
       danger of unfair prejudice to the defendant.

State v. Richards, 879 N.W.2d 140, 145 (Iowa 2016) (second alteration in original)

(emphasis omitted) (quoting State v. Sullivan, 679 N.W.2d 19, 25 (Iowa 2004)).

       We find the record inadequate to address this claim on direct appeal. We

cannot discern counsel’s state of mind when he declined to object to the landlady’s

testimony. See Clay, 824 N.W.2d at 500. Accordingly, we preserve the prior-bad-

acts claim for possible postconviction-relief proceedings to allow trial counsel an

opportunity to respond to Lopez’s claim. See State v. Harrison, 914 N.W.2d 178,

208–09 (Iowa 2018) (quoting State v. Soboroff, 798 N.W.2d 1, 8 (Iowa 2011)).

       D. Willingness to Take a Polygraph

       In an issue preserved for our review, Lopez contends the district court

abused its discretion by excluding evidence of his “consciousness of innocence.”

The excluded evidence was an uncounseled statement by Lopez to law

enforcement agreeing to polygraph testing.
                                         22


       On the day R.A. died, Iowa Division of Criminal Investigation Agent Don

Schnitker interviewed Lopez. Clive Police Detective Vernon Lukehart watched the

interview by closed-circuit television. Toward the conclusion of the interview,

Agent Schnitker asked Lopez if he would be willing to submit to a polygraph

examination. Lopez agreed. But before the agent conducted the polygraph, Lopez

received word of the toddler’s death. Lopez returned to the hospital. He then

talked to a lawyer, who advised against taking the polygraph.

       Before trial, the State objected to the defense plan to offer Lopez’s

statement of willingness to take the polygraph.       The prosecutor urged if the

defense could offer Lopez’s initial agreement, the State would be entitled “to bring

up the fact that he asked not to take the polygraph because he hired a lawyer.”

The district court sided with the State, reasoning

       as you all know, those lie detector results are inherently unreliable in
       Iowa. And, if the results are unreliable regardless of what those
       results might have been, if this process had gotten that far, to me,
       that makes any inferences arising from taking or not taking the
       polygraph also inherently unreliable.

Lopez asserts the district court’s exclusion of this evidence amounted to an abuse

of discretion, particularly when the State was able to introduce the remaining

content of his interview through the testimony of Agent Schnitker and Detective

Lukehart.

       Polygraph results are inadmissible in Iowa based on concerns of fairness

and reliability. See, e.g., State v. Conner, 241 N.W.2d 447, 458–59 (Iowa 1976);

State v. Countryman, 573 N.W.2d 265, 266 (Iowa 1998). While our supreme court

has not decided whether willingness to take a polygraph should be treated

differently, the majority of jurisdictions that have encountered this question have
                                         23

excluded such evidence. See DeBlase v. State, ___ So.3d ___, ___, 2018 WL

6011199, at *36 (Ala. Crim. App. 2018) (collecting cases and observing “numerous

other jurisdictions have addressed the issue and they have almost universally held

that a defendant’s offer to take a polygraph test is generally inadmissible.”); see

also 3 Barbara E. Bergman, Nancy Hollander, & Theresa M. Duncan, Wharton’s

Criminal Evidence § 13:42 (15th ed. Oct. 2018 Update) (“[M]ost jurisdictions also

exclude a defendant’s statement of willingness to take a polygraph on the grounds

of relevance.”); 7 Clifford S. Fishman & Anne T. McKenna, Jones on Evidence §

53:14 (Dec. 2017 Update) (providing a state-by-state rundown on admissibility of

polygraph evidence, including willingness to take a polygraph); George E. Dix et

al., McCormick on Evidence § 206 (7th ed. June 2016 Pocket Part) (“First, there is

the traditional rule that the test results are inadmissible when offered by either

party, either as substantive evidence or as relating to the credibility of a witness.

As a corollary, the willingness or unwillingness of a party or witness to submit to

examination is also inadmissible.” (footnotes omitted)).

       Courts excluding polygraph-willingness reason because the results of the

polygraph are inadmissible, an offer to submit to a test

       is a self-serving act undertaken with no possibility of any risk. If the
       offer is accepted and the test given, the results cannot be used in
       evidence whether favorable or unfavorable. In these circumstances,
       the sincerity of the offer can easily be feigned, making any inference
       of innocence wholly unreliable.

Commonwealth v. Martinez, 769 N.E.2d 273, 278–79 (Mass. 2002).

       Without guidance from our supreme court, we decline to impose a bright-

line restriction on admissibility of willingness to take a polygraph examination. We

can imagine a scenario where a suspect’s offer to take a polygraph test would be
                                            24

relevant to the state of mind of the person making the offer.14 See State v.

Santana-Lopez, 613 N.W.2d 918, 921 (Wis. Ct. App. 2000) (finding an offer to take

a polygraph may reflect a consciousness of innocence if the person making the

offer believes the test would be possible, accurate, and admissible). But that

scenario is not before us now.

       And as the prosecutor emphasized before trial, Lopez’s original assent to

the agent’s offer of a polygraph was quickly revoked after R.A.’s death and Lopez

obtained counsel.      Allowing his initial willingness into evidence under these

circumstances would have created a substantial risk of confusing the issues and

misleading the jury. See Iowa R. Evid. 5.403. Accordingly, the district court did

not abuse its discretion.

       E. Medical Examiner’s Manner-of-Death Testimony

       Lopez next contests the district court’s ruling on the admissibility of the

medical examiner’s opinion on the manner of death. Before trial, the defense

asked the court to bar Dr. Schmunk from sharing his opinion R.A. died as a result

of a homicide, or in other words, by “the act of another person on her.” The court

allowed the testimony.

       On appeal, Lopez cites State v. Tyler, in which our supreme court

determined expert testimony on manner of death was inadmissible when the

opinion was based “largely on witness statements or information obtained through



14
    Like evidence of consciousness of guilt, evidence of consciousness of innocence may
be “probative to actual guilt with respect to the crime charged[.]” See State v. Wilson, 878
N.W.2d 203, 212 (Iowa 2016) (describing the parameters for admission of evidence of
flight to prove consciousness of guilt). But here, Lopez did not offer any additional
evidence supporting an inferential chain between his willingness to take a polygraph and
his consciousness of innocence. See id. at 213.
                                         25


police investigation.” 867 N.W.2d at 162 (citing Iowa R. Evid. 5.702). Under those

circumstances, the manner-of-death opinion was unhelpful to the jury. Lopez

contends Dr. Schmunk’s testimony was likewise improper because Dr. Schmunk

noted Lopez’s statement was “important in what it lacked” and was inconsistent

with the autopsy findings.

       Lopez’s reliance on Tyler is misplaced. In Tyler, the expert witness admitted

he was “unable to reach a conclusion” on both cause and manner of death, and

the “only way he reached his final opinions” was through referencing the

defendant’s statements to police. 867 N.W.2d at 164. By contrast, Dr. Schmunk

testified he reached his opinion on the manner of death “irrespective really of the

information that was given to [him] prior to the death.” In his deposition, Dr.

Schmunk noted:

       Had [Lopez] provided a story that was consistent with the findings,
       then that would have possibly, depending on what the story was,
       would have possibly given me something else to consider. However,
       it would be extremely unlikely to the point that I can’t imagine a
       scenario that would have caused the injuries in this case, other than
       at the hands of another.

       Unlike the expert in Tyler who based his opinion on witness statements, Dr.

Schmunk testified his manner-of-death opinion was based on his autopsy findings,

but witness statements potentially could have changed his findings. Cf. id. at 163–

64. The district court properly admitted Dr. Schmunk’s testimony about the manner

of death. See id. (“When a medical examiner bases his or her opinion on cause

or manner of death primarily on the autopsy, such opinions will likely assist the jury

in understand the evidence and would ordinarily be admissible.”).
                                            26


       F. Prosecutorial Error

       In his final claim, Lopez flags an alleged error in the State’s closing

argument.15 Like the first two issues on medical certainty addressed earlier in this

decision, this allegation centers on the expert testimony. In rebuttal, the prosecutor

argued:

       You have the doctors that are all telling us that the most reasonable
       explanation for this is inflicted trauma and abuse. There’s a possible
       possibility, this rare circumstance. But think of it like this. That’s a
       rare circumstance for each and every one of those nine injuries. That
       would be like winning the lottery nine times in one event. That’s not
       reasonable.

       Defense counsel made a record outside of the presence of the jury,

objecting to the prosecutor’s “phony math” analogy. Counsel asked the court to

admonish the jurors to disregard the State’s argument concerning statistical

probability, but did not believe the statement rose to the level of “mistrial material”

at that point. In support of its objection, the defense cited People v. Collins16 as

the “seminal case” on improper use of mathematical-probability arguments.




15  Our supreme court recognizes a distinction between misconduct and less egregious
missteps by a prosecutor. Schlitter, 881 N.W.2d at 394. Prosecutorial misconduct marks
an intentional breach or reckless disregard of clear standards of law or professional
obligations. Id. Prosecutorial error covers instances where the State’s attorney uses
reasonable care but exercises poor judgment or makes a mistake. Id.
16
   In People v. Collins, the prosecutor called a mathematician in an attempt to establish,
assuming the crime was committed by any two people with the distinct characteristics of
those seen by the eye witnesses, there was “an overwhelming probability” the crime was
committed by “any couple answering such distinctive characteristics.” 438 P.2d 33, 36–
37 (Cal. 1968). The prosecutor then “proceeded to have the witness [a]ssume probability
factors for the various characteristics which he deemed to be shared by the guilty couple
and all other couples answering to such distinctive characteristics.” Id. Then, “[a]pplying
the product rule to his own factors,” the prosecutor concluded the probability “any couple
possessed the distinctive characteristic[s] of the defendants” was one in twelve million.
Id. The court determined this amounted to prejudicial error because the testimony lacked
foundation and distracted the jury. Id. at 38.
                                           27

           After taking a brief recess to review Collins, the district court overruled

defense counsel’s objection and declined to instruct the jury to disregard the lottery

statement. But, upon the jurors’ return, the court did remind them that closing

arguments were not evidence and the State had the burden of proving Lopez guilty

beyond a reasonable doubt.

           On appeal, Lopez argues the State’s lottery statement was prosecutorial

error for two related reasons: (1) it was “not a reasonable inference from the

evidence” and (2) it was “improper use of a statistical analogy.” Supporting the

first ground, Lopez notes the doctors’ opinions that it would be rare for a highchair

fall to cause the grave injuries suffered by R.A. came with no calculation of

mathematical probability. Accordingly, Lopez argues, the lottery analogy was not

a fair summary of the experts’ conclusions. Further, Lopez points to the lack of

evidence regarding the odds of winning the lottery. Without such evidence, Lopez

maintains it is baseless to compare the likelihood of R.A.’s injuries with winning the

lottery.

           On the second ground, Lopez asserts the prosecutor improperly invoked

the “product rule,” which suggests “the probability of the joint occurrence of a

number of a mutually independent events is equal to the product of the individual

probabilities that each of the events will occur.” See id. at 36. Lopez quotes Wilson

v. State, which states, “A problem arises when dependent variables are treated as

independent ones.” 185 S.W.3d 481, 487 (Tex. Crim. App. 2006) (Johnson, J.,

concurring). Lopez points to the lack of evidence regarding the independence of

each injury R.A. sustained, maintaining without such proof, the product rule cannot
                                              28


be applied. For these reasons, Lopez concludes, he was deprived of his right to a

fair trial.17

         To prevail in his claim of prosecutorial error, Lopez must first prove the

statement was improper, and second, it resulted in prejudice. See State v. Graves,

668 N.W.2d 860, 869 (Iowa 2003); see also Schlitter, 881 N.W.2d at 394 (noting

the Graves test “easily translate[s] to an evaluation of prosecutorial error”). “In

closing arguments, counsel is allowed some latitude.                   Counsel may draw

conclusions and argue permissible inferences which reasonably flow from the

evidence presented.” State v. Thornton, 498 N.W.2d 670, 676 (Iowa 1993) (citing

State v. Phillips, 226 N.W.2d 16, 19 (Iowa 1975)). But counsel cannot “create

evidence or misstate the facts.” Id. (citing Phillips, 226 N.W.2d at 19).

         Assuming without deciding the prosecutor’s comment was improper, we

conclude Lopez suffered no prejudice. See Graves, 668 N.W.2d at 869 (“It is the

prejudice resulting from the misconduct, not the misconduct itself, that entitles a

defendant to a new trial.” (quoting State v. Piper, 663 N.W.2d 931, 894 (Iowa

2003), overruled on other grounds by State v. Hanes, 790 N.W.2d 545 (Iowa

2010))).        In determining whether a party was prejudiced by prosecutorial

misconduct or error, we consider

         (1) the severity and pervasiveness of the misconduct; (2) the
         significance of the misconduct to the central issues in the case; (3)
         the strength of the State’s evidence; (4) the use of cautionary

17
  The State argues Lopez failed to preserve error on this issue because defense counsel
did not request a mistrial. We disagree with the State’s error-preservation argument—
defense counsel’s objection was sufficient to preserve Lopez’s claim. See Neiderbach,
837 N.W.2d at 209 (distinguishing need to move for mistrial to preserve error on
prosecutorial misconduct claim where the objection is sustained as laid out in Krogmann,
804 N.W.2d at 526, with district court overruling objection, where objection is sufficient to
preserve error, explaining “[a] motion for mistrial would be futile when the district court has
overruled the objection to the statements giving rise to the grounds for a mistrial.”).
                                          29


       instructions or other curative measures; and (5) the extent to which
       the defense invited the misconduct.

Id. at 877; see also Schlitter, 881 N.W.2d at 394. We can envision a case where

prejudice could result from an isolated incident of prosecutorial error. But that case

is far from the norm. Ordinarily, courts will find prejudice only where the prosecutor

has persistently injected harmful information into the jury trial. See Neiderbach,

837 N.W.2d at 210.

       Like in Neiderbach, the prosecutor here made a single statement, arguably

mischaracterizing the expert testimony.        See id.   The prosecutor made the

statement against a backdrop of extensive expert testimony on the perceived

unlikelihood of R.A. incurring her constellation of injuries in a manner consistent

with Lopez’s explanation. The State presented strong evidence R.A.’s injuries—

fatal and otherwise—did not result from an accidental fall from her high chair. We

affirm the district court’s ruling on the grounds Lopez failed to demonstrate

prejudice from the alleged error. See id. (“[The appellant] cited no case on point

holding a new trial was required because the prosecutor misstated an expert’s

testimony.”).

       Our finding of harmless error finds support in defense counsel’s handling of

the objection at trial. Counsel asked the court to admonish the jurors to disregard

the lottery statement, but did not believe the error was serious enough to prompt

a mistrial. If the prosecutor’s mistake did not merit a mistrial at that time, when the

verdict had yet to be delivered, it does not mandate a new trial now.

       Finding sufficient evidence, no abuse of discretion in the evidentiary rulings,

and no breach of duty by counsel, we affirm. We preserve Lopez’s ineffective-
                                           30


assistance     claim   relating   to   prior-bad-acts   evidence   for   postconviction

proceedings.

      AFFIRMED.
