                        Docket No. 100055.

                       IN THE
                  SUPREME COURT
                         OF
                THE STATE OF ILLINOIS



THE PEOPLE OF THE STATE OF ILLINOIS, Appellee, v. DAVID
                 A. HARI, Appellant.

                  Opinion filed January 20, 2006.



   JUSTICE FITZGERALD delivered the judgment of the court,
with opinion.
   Chief Justice Thomas and Justices Freeman, McMorrow,
Kilbride, Garman, and Karmeier concurred in the judgment and
opinion.



                             OPINION

    Defendant David A. Hari admitted to shooting his wife and her
lover. The principal issue at defendant=s trial was his culpability for
those shootings. Thus the evidence adduced concerned the opposing
issues of whether defendant planned the crime or whether defendant
was relieved of culpability due to purported involuntary intoxication
from his prescription Zoloft medication in combination with other
factors. The circuit court of Ford County denied defendant=s proffered
involuntary intoxication instruction, finding Illinois law disallowed
such a defense in the absence of evidence that the defendant=s
intoxication was the result of Atrick, artifice, or force.@ The jury
thereafter found defendant guilty of the attempted first degree murder
of his estranged wife, Lisa Hari, and the first degree murder of her
lover, Jeff Thomas. The court sentenced defendant to 48 years=
imprisonment on the murder count and a consecutive 25-year prison
term on the attempt count. The appellate court affirmed. 355 Ill. App.
3d 449.
    We do not decide here whether defendant is relieved of
culpability due to the alleged side effects caused by the ingestion of
Zoloft. Rather, we interpret the involuntary intoxication statute (720
ILCS 5/6B3 (West 2002)) and the evidence adduced at trial to
determine if defendant was entitled to an involuntary intoxication
jury instruction. We further consider issues related to the testimony
of an in custody informant, Tracy Parker. Because we find that the
jury should have been given an involuntary intoxication instruction,
we reverse and remand for a new trial.

                           BACKGROUND
      Although the State introduced several witnesses presenting
evidence of premeditation, we set out background facts and focus on
the issues at hand relating to the involuntary intoxication and the
testimony of the jailhouse informant, Tracy Parker. Lisa and
defendant were married in 1989. They had two children, Zachary, 12
years old at the time of trial, and Kyle, six years old at the time of
trial. Lisa was a daycare provider out of her house for six years.
Defendant worked at a lumber yard. The family lived in a house in
the central Illinois farm community of Paxton. Zack and his dad
would often go hunting together, sometimes using a .22-caliber rifle.
The couple had known Jeff Thomas and his wife, Julie Arnold
Thomas, for approximately four years. The Thomases had two
children: Jarrett, 13 at the time of trial, and Jordan, almost 11 at the
time of trial. Lisa described the relationship with her husband around
Christmastime of 2001 as Avery distant,@ they Adidn=t spend much
time together,@ and Awere not getting along well.@ According to the
record, Lisa became romantically involved with Jeff Thomas
sometime prior to that Christmas. According to Lisa, on December
25, 2001, she told defendant of the affair. Lisa filed for a divorce
from defendant on January 10, 2002.
     On February 4, 2002, defendant went to see Dr. David John
Hagan, a family physician. The doctor noted that defendant related
that he was not sleeping and had lost weight, but was beginning to get

                                  -2-
his weight back. Dr. Hagan felt defendant Awas under significant
stress and was depressed because of the stress he was going through
in terms of his family life and the divorce.@ Defendant denied any
suicidal thoughts or ruminations. The doctor admonished him not to
drink alcohol and prescribed defendant a Astarter pack@ of Zoloft, an
antidepressant, at 25 milligrams a day. Dr. Hagan started defendant
on a lower dosage than he normally prescribed because of defendant=s
alcohol use since his separation from his wife. He also told defendant
to call him if there were any side effects. Dr. Hagan did not know that
defendant was taking any additional medication, nor did he warn him
about combining Zoloft and Tylenol PM.
     At approximately 6 p.m. on February 10, 2002, Lisa was on the
telephone with her brother, Scott Sherfey. Lisa heard a noise in the
basement which sounded like someone cocking a rifle. According to
Scott, Lisa walked down to the basement and said, AOh, my God, he
is here.@ Defendant was coming out of the laundry room with the .22-
caliber rifle. Defendant started firing as Lisa turned toward the
staircase and tried to get away. Defendant shot Lisa three times in the
left flank, upper right arm, and the right side of her head. Thomas
arrived, and he stopped his truck in the driveway with the engine still
running. Thomas was approximately 70 feet from defendant in the
middle of the street in his naval reserve uniform. Defendant shot him
four times from behind: in the left forearm, above the right buttock,
in the back, and in the upper shoulder or neck area. The police
apprehended defendant approximately three or four hours later in
Roberts, Illinois. Defendant did not seem physically impaired to the
police officers. Lisa was admitted to intensive care, underwent
surgery, and was later released. Thomas died days later as the result
of a severed carotid artery.
     The State=s information charged defendant with the offense of
first degree murder (720 ILCS 5/9B1(a)(1) (West 2000)), alleging that
he, without lawful justification and with the intent to kill or do great
bodily harm to Jeff Thomas, shot Thomas causing his death. The
State also charged defendant with attempted first degree murder (720
ILCS 5/8B4(a), 9B1(a)(1) (West 2000)), alleging that he, with the
intent to commit first degree murder, performed a substantial step
toward the commission of that offense by shooting Lisa Hari with a
.22-caliber weapon without lawful justification and with the intent to
kill.

                                  -3-
    Among the State=s witnesses was Tracy Parker, an in-custody
witness who shared a jail cell with defendant at the Ford County jail.
Tracy Parker had a Along criminal record.@ He was convicted in 1992
of aggravated battery and in 1994 he was convicted of burglary and
arson. In 2000, he was convicted of three counts of burglary. One of
those 2000 counts involved a gun store, which led to the federal
offense of possession of firearms by a felon. While serving the
sentence on the federal charge, he was charged with the offense of
conspiracy to escape. He was convicted in federal court of conspiracy
to escape and was awaiting sentencing at the time of trial. Parker
testified that defendant was his cellmate in Ford County jail for seven
weeks, commencing on September 13, 2002. He testified that
defendant was asking him to help him escape from prison. After a
few weeks, defendant started talking about his case. Parker testified
that defendant told him that he used to watch the house and his wife
and Thomas enter and exit. Defendant stated the weekend he was
moving out of the house he was angry because he had found pictures
of Lisa in lingerie, wrapped in a towel, a picture of her blowing a kiss
and pictures Thomas took of her. Defendant told him that he took a
.22-caliber rifle out of a gun cabinet and hid it in a utility room in the
basement, Aso he could have it for later.@
    Defendant told him about the weekend of the shooting. According
to Parker, defendant went to the house, retrieved the rifle, and waited
in the basement for Lisa and Thomas to come home. Defendant told
him that he shot Thomas and then he shot his wife. Defendant told
him he accessed the house by borrowing some keys from an older
religious lady that lived next door, and that he copied her key for his
own use.
    On cross-examination, Parker testified that he had pleaded guilty
to the federal conspiracy to escape charge on October 30, 2002. On
November 1, 2002, he approached corrections officers about
defendant=s case. Parker admitted that he was aware of discovery
materials that defendant kept in the cell. At times, Parker was in the
cell while defendant was not, and Parker admitted that he had the
ability to look at the materials when defendant was away because
there were no lockers. Parker acknowledged that his attorney
discussed sentencing possibilities with him, but Parker claimed that
cooperation in a state case could not help him receive a downward
sentencing departure in the federal case. Parker testified, AIt can=t help

                                  -4-
me either way.@ Parker testified that he did not expect anything in
exchange for his testimony against defendant, nor was he promised
anything. Parker denied that he wanted anything the day after his
federal conviction when he contacted a correctional officer, Sargeant
Sherfey, the sister of Lisa Hari.
    Dr. Robert Mitrione testified on behalf of the defendant. In
November 2002, defense counsel hired Dr. Mitrione to evaluate
defendant=s mental health. He testified that defendant=s depression
began with the knowledge that his wife was having an extramarital
affair with Thomas. Defendant was not sleeping and was using
alcohol regularly. He noted that Dr. Hagan diagnosed defendant with
Adepression@ and that defendant=s description of his symptoms
conformed to Amajor depression@ in the Diagnostic and Statistical
Manual IV (DSM-IV).
    He explained that Zoloft is a selective serotonin reuptake
inhibitor (SSRI), designed to increase serotonin in the brain. It is Anot
unusual@ for these medications to cause paradoxical or adverse
reactions, depending on the patient. Dr. Mitrione also explained that
the Zoloft package insert contained a listing of side effects which was
an exact copy of the listing in the Physicians= Desk Reference (PDR).
Dr. Mitrione testified that the stage at which adverse reactions most
frequently occur is when medication is first taken or there is a change
in dosage. Dr. Mitrione cited conflicting medical literature, some of
which reports violent and suicidal adverse reactions at the beginning
stage of taking Zoloft or SSRIs. Dr. Mitrione stated that the PDR
contains a caution to mixing Zoloft with alcohol and other drugs that
are metabolized in the liver. He testified that liver enzyme reduction
or enzyme depletion can cause a toxic reaction.
    Dr. Mitrione testified at length about his interview with defendant
concerning the shootings. Defendant told him that on February 10,
defendant had been on Zoloft for six days and had also been taking
Tylenol PM. Tylenol PM has an active ingredient called
diphenhydramine, which is an antihistamine commonly found in
medications such as Benadryl. Dr. Mitrione testified that the PDR
does not specifically warn of the combination of Zoloft and
diphenhydramine. Dr. Mitrione explained, however, that
diphenhydramine is officially used for allergies, but it is also a
psychoactive that can be used for sedation. The PDR warns of the use


                                  -5-
of Zoloft with some drugs that are metabolized in the liver, or use if
the liver is otherwise impaired. The combination of Zoloft and
diphenhydramine is problematic, therefore, because of this liver
metabolism.
    Dr. Mitrione testified that defendant told him that after he began
taking Zoloft, he became more anxious, more intense, and his
thinking became less clear. Dr. Mitrione testified that defendant=s
symptoms in those six days corresponded to the reactions listed on
Zoloft=s package insert and in the PDR. He stated that defendant
suffered a litany of side effects including Aagitation, trimmer [sic],
abdominal discomfort, fatigue, tiredness, somnolence, and some
confusion.@ He also experienced malaise, depression, Ateeth grinding,
chinning the jaw, emotional ability, abnormal dreams, paranoia
reaction,@ and insomnia. Defendant also displayed some symptoms of
akathisiaBwhich is a kind of agitation Alike an itch that can=t be
scratched@Bwhich is indicated by tremulousness, restlessness, jaw
clenching, pacing, or general nervousness. Akathisia has a mental
component which intensifies worry and is very distracting to an
individual. In the week before the shooting, defendant had Ahigh
depression, increased fatigue, increased malaise, increased agitation
and then new symptoms were the jaw clinching, the nightmares,
abdominal discomfort, tremulousness and some intensified
ruminations and thought processes.@ Some of these symptoms,
particularly the sleeplessness, were confirmed by some of defendant=s
family and coworkers at trial. Mitrione testified that defendant told
him he developed a sense of things seeming strange and not being
real, Alike watching himself go through@ things but not being part of
itBAlike it wasn=t him.@
    Dr. Mitrione related what defendant told him about the events on
February 10. Defendant told him he had been sleeping only one or
two hours a night the week prior to the incident. On that day, he went
back to the house to retrieve the .22-caliber weapon so he could later
go hunting with his son. He had forgotten to take it with him when he
packed because of the fight with his wife. ASo he decided and
somewhat illogically@ that he had to get it without his wife knowing
about it, because if his wife found out about it, she would use it
against him in a custody dispute. The .22-caliber rifle was behind the
water heater in the basement. Defendant said he put it there because
there is a Acrazy guy in the neighborhood that he didn=t trust.@

                                 -6-
Defendant also said there was a rottweiler in the neighborhood. In Dr.
Mitrione=s words, defendant described the shootings like a Afuzzy
dream.@ Dr. Mitrione testified that defendant told him:
        AShe you know, made some unpleasant remarks to him and
        somewhat threatening remarks, and he said the gun just
        started going off, and that at the time it didn=t seem like it
        wasBit=s my word neutral. He didn=t describe it that way, but
        at the time it didn=t seem right. It didn=t seem wrong. It just
        was, and that it was, it was like he was watching himself go
        through the motions; that he went on. *** [He left] and Jeff
        Thomas happened to be pulling in the driveway at the same
        time, and the same sort of event occurred. Thomas started
        complaining at him, and, again, the firearm just started going
        off. He didn=t recall leaving the scene, didn=t recall too much
        except that he was out driving around the country.@
Dr. Mitrione opined that defendant=s impaired memory was not
unusual.
    Dr. Mitrione diagnosed defendant with Amajor depression, alcohol
dependence,@ and a Aprobable paranoid personality disorder.@
Mitrione explained that people with a paranoid personality disorder
are very suspicious, rigid thinkers and more susceptible to adverse
drug reactions. Dr. Mitrione opined that, to a reasonable degree of
medical and psychiatric certainty, defendant suffered from
involuntary intoxication from the adverse effects of the combination
of Zoloft and diphenhydramine, with the lack of sleep, major
depression, and alcohol dependency as contributing factors. Dr.
Mitrione further opined, to a reasonable degree of medical and
psychiatric certainty, that the involuntary intoxication deprived him
of the substantial capacity to appreciate the criminality of his acts or
conform his conduct to the requirements of the law at the time of the
shooting. Defendant=s intoxication was involuntary because:
        AMr. Hari went through things that were fairly reasonable that
        most any person would do in terms of addressing his problem,
        at least, from kind of a medical basis. He looked for some
        sleeping medication that would be helpful to aid his sleeping
        and Tylenol PM is promoted as a sleep aid. He tried that. ***
        He still didn=t experience any relief. He followed up with a
        visit to his physician who prescribed him some medicine, you

                                  -7-
         know, with the encouragement. It may not work right away,
         but after a little while, you are going to feel better. Certainly,
         he had every expectation to think that he would feel better.@
Dr. Mitrione testified that his diagnosis of Ainvoluntary Zoloft
intoxication@ was a recognized disease, defect, or derangement within
DSM-IV. However, the word Aintoxication@ is misleading because it
does not have to do with alcohol, but rather is a toxic reaction. Dr.
Mitrione explained that an adverse drug reaction would affect an
individual=s perception of events, but, in contrast to alcohol
intoxication, it would not result in slurred speech or the inability to
drive or walk in a straight line.
     Defendant also submitted into evidence the package insert for the
Zoloft. This insert consists of a 92-inch by 16-inch two-sided sheet,
containing four columns on each side, typed in fine print and
depicting several tables. One section discusses events observed
during the clinical trials of over 4,000 subjects during the
premarketing assessment of Zoloft. According to the insert, AIt is
important to emphasize that although the events reported occurred
during treatment with ZOLOFT, they were not necessarily caused by
it.@ The insert states, Ainfrequent adverse events are those occurring in
1/100 to 1/1000 patients.@ Under the subheading Apsychiatric
disorders,@ infrequent adverse events listed include Adepression,
amnesia, paroniria, teeth-grinding, emotional lability, apathy,
abnormal dreams, euphoria, paranoid reaction, hallucination,
aggressive reaction, aggravated depression, [and] delusions.@
      Dr. Robert Chapman testified as a rebuttal witness on behalf of
the State. Defendant=s first attorney, the Ford County public defender,
hired Dr. Chapman to examine defendant on March 27, 2002. He was
directed to examine defendant for any psychiatric findings, but
particularly for sanity. Dr. Chapman administered a multiple-choice
psychiatric test and also conducted a two hour face-to-face
examination. Chapman found that defendant suffered impaired
concentration, rumination, and increased drinking after his wife had
the extramarital affair. He made several diagnoses after the March 27,
2002, exam. He diagnosed defendant with the following disorders:
personality disorder not otherwise specified, with obsessive
compulsive and attention deficit disorder features; adjustment
disorder or unadjusted-to stress with depressed mood; and social


                                   -8-
anxiety disorder or painful shyness, fear, and anxiety of being around
strangers. Dr. Chapman found that defendant was tense, irritable,
preoccupied, very angry, depressed, and full of resentment and
rumination over his problems, had suicidal thoughts, strong feelings
of inadequacy, uncertainty about the future, and a tendency to
misunderstand the motives of others. He noted that defendant also
had an adjustment disorder with a depressed mood in 1988 following
a stressful situation. Dr. Chapman testified that defendant=s paranoid
personality feature has been present since he was 18 years old. As to
the question of legal insanity, Dr. Chapman opined that defendant
was not impaired by any mental disease, defect, or condition to cause
him to lack substantial capacity to appreciate the criminality of his
conduct.
     Defendant related his history with Zoloft to Dr. Chapman.
According to Dr. Chapman, Zoloft is part of the new generation of
antidepressants. He testified that it has a very favorable Aside effect
profile,@ meaning that, in general, patients have few side effects, if
any. This helps with efficiency and compliance in taking the drug
because patients are more likely to take it if there are no side effects.
Twenty-five milligrams a day for a week is a typical starting,
subtherapeutic dose. By the time of the interview, March 27, 2002,
defendant had been taking the 50-milligram dosage for several weeks
because he continued to take the drug after the shootings and he had
begun to feel some relief from his depression. Defendant did not
mention any side effects from the Zoloft. Defendant did not mention
that he had taken Tylenol PM at any time before the shootings. The
doctor was not aware of any adverse reactions between Zoloft and
Tylenol PM=s ingredient diphenhydramine. Chapman admitted that
diphenhydramine impacts the enzymes of the liver. Chapman agreed
that Zoloft can have some paradoxical side effects in 1% or fewer of
all users, and a low dose could produce adverse reactions in some
individuals. Chapman admitted that restlessness and pacing are
indicative of akathisia, a movement disorder, and that akathisia,
gastrointestinal problems, restlessness, depersonalization, irritability,
personality changes, hostilities and paranoia symptoms can develop
while a patient is on Zoloft.
     At the March 27 interview, Dr. Chapman did not evaluate
defendant for involuntary intoxication or consider whether
involuntary intoxication deprived defendant of his ability to conform

                                  -9-
his conduct to the law. However, he did evaluate whether the mental
disorder was from a toxic substance, drug, or alcohol. Dr. Chapman
stated, AWhat [defendant did] *** was not consistent with any toxic
reaction to any medicines or any other substance.@ On redirect, Dr.
Chapman testified that defendant told him that he went to the house
that day to retrieve the rifle because he had earlier forgotten it when
he moved out. He also stated that defendant simply said with regards
to the shooting that Ait was kind of vague to him.@ Dr. Chapman
stated that it Ais not uncommon for people involved in an acute
stressful situation, to have very, very sketchy memory about some of
the events. That=s not uncommon, and that was this case too.@
     Dr. Hagan also testified as a rebuttal witness. Dr. Hagan did not
know that defendant was also taking Tylenol PM, which contains
diphenhydramine. The Zoloft starter pack is a sample pack that
contains a 25-milligram dosage for the first seven days of use. The
first week on Zoloft is generally considered Asubtherapeutic@ because
the 25-milligram dosage acclimates the body to the drug, but does not
yet act as an antidepressant on the patient. Dr. Hagan started him on a
lower dosage than he normally prescribed because of defendant=s
increased alcohol use since his separation from his wife. Dr. Hagan
was not aware of any adverse affects of the combination of Tylenol
PM and Zoloft. He generally disapproved of Tylenol PM. He was
also unaware of adverse affects of Zoloft with drugs that affected
liver enzymes. It was beyond his expertise as to how the body
metabolized diphenhydramine. In his experience, he had no
knowledge of Zoloft causing involuntary intoxication. In the doctor=s
2000 PDR, he could find no drug interaction between
diphenhydramine and Zoloft.
      At the jury instructions conference, defense counsel tendered
jury instructions for an affirmative defense of involuntary
intoxication. See 720 ILCS 5/6B3 (West 2002). The court found that
the issue of intoxication was raised by defendant=s evidence and
expert testimony. The trial court, however, denied the requested
instruction, stating that the involuntary intoxication may only be due
to Atrick, artifice, or force,@ following the existing case law cited by
the State of People v. Downey, 162 Ill. App. 3d 322 (1987), People v.
Larry, 144 Ill. App. 3d 669 (1986), and People v. Walker, 33 Ill. App.
3d 681 (1975). The trial court instructed the jury on the defense of
insanity, and, following closing arguments, the jury found defendant

                                 -10-
guilty of first degree murder and attempted first degree murder.
     On November 26, 2002, the day after the jury returned verdicts of
guilty against defendant, Ford County State=s Attorney Tony Lee
wrote a letter to an assistant United States Attorney handling Parker=s
federal case. Lee=s letter stated that while no requests or promises
were made, he Awanted to make [the federal prosecutor] aware of
Parker=s assistance@ in defendant=s trial. Lee stated: AParker was
helpful and cooperative and provided useful information in our
successful prosecution of the defendant.@
     In December 2002, defendant filed a motion for judgment of
acquittal or for a new trial. Defendant argued that the court
improperly refused to instruct the jury on involuntary intoxication,
and the court improperly restricted defendant=s cross-examination of
Tracy Parker concerning how much good time he could accrue on his
state and federal sentences for cooperation. The trial court denied the
motion. The trial court sentenced defendant to 48 years in prison on
the murder count and a consecutive term of 25 years on the attempted
first degree murder count. In February 2003, defendant filed a motion
to reconsider, which the court denied.
     The appellate court affirmed. 355 Ill. App. 3d 449. After finding
that the involuntary intoxication statute was ambiguous, the court
nevertheless set forth the dictionary definition of Ainvoluntarily,@ and
stated Athat intoxication caused by an unexpected adverse reaction to
prescribed medication falls within the ordinary meaning of the term
>involuntarily produced.= @ 355 Ill. App. 3d at 459. It held, AWhen
evidence is presented showing a defendant ingested prescribed
medication and suffered an adverse reaction whereby he was unable
to control his own will when he committed a criminal act, a defendant
is entitled to a jury instruction on the defense of involuntary
intoxication.@ 355 Ill. App. 3d at 459. The appellate court, however,
found that the failure to give a tendered instruction on this affirmative
defense was harmless error, because its review of the record
demonstrated that the State had presented clear and convincing
evidence rebutting the affirmative defense. 355 Ill. App. 3d at 459.
The appellate court additionally found that defendant forfeited the
argument that his convictions must be reversed because the State
failed to correct Tracy Parker=s assertion that he had nothing to gain
from his testimony because he did not raise the issue in his posttrial


                                 -11-
motion. 355 Ill. App. 3d at 461. The appellate court also rejected
defendant=s argument that the trial court denied him his constitutional
right to cross-examine Parker about his motive to lie. The appellate
court held that even if this was error, defense counsel was given
adequate latitude to establish Parker=s alleged bias. 355 Ill. App. 3d at
463. Thus, any error was harmless beyond a reasonable doubt. 355
Ill. App. 3d at 463. We granted defendant=s petition for leave to
appeal. See 177 Ill. 2d R. 315(a). On the law issues before us, our
review proceeds de novo. People v. Willis, 215 Ill. 2d 517, 524
(2005).

                              ANALYSIS
    We first address whether the Criminal Code of 1961 permits the
defendant=s instruction pertaining to involuntary intoxication.
    Illinois law provides for an affirmative defense where conduct is
produced by an intoxicated or drugged condition. 720 ILCS 5/6B3
(West 2002). The Code provides:
             AA person who is in an intoxicated or drugged condition is
         criminally responsible for conduct unless such condition is
         involuntarily produced and deprives him of substantial
         capacity either to appreciate the criminality of his conduct or
         to conform his conduct to the requirements of law.@ 720 ILCS
         5/6B3 (West 2002).
    Defendant argues that intoxication resulting from the unexpected
and unwarned adverse side effects of medication prescribed by a
physician falls within the plain meaning of the term Ainvoluntarily
produced@ in the statute. Further, according to defendant, the trial
court=s limit of this language to trick, artifice, or force is too narrow.
The State responds that the term is not defined in the Code. Further,
according to the State, the term Ainvoluntarily produced@ can be
reasonably interpreted to Aboth include and exclude@ unwarned side
effects of prescription medication voluntarily taken as directed. The
State points to previous case law interpreting involuntary intoxication
as strictly encompassing intoxication induced only by an outside
influence such as trick, artifice, or force as support for this alternate
narrow interpretation. We agree with defendant.
    The cardinal rule of statutory construction is to give effect to the
intent of the legislature. People v. Blair, 215 Ill. 2d 427, 442 (2005).

                                  -12-
The best evidence of legislative intent is the language used in the
statute, which must be given its plain and ordinary meaning. Blair,
215 Ill. 2d at 442-43. It is never proper for a court to depart from
plain language by reading into the statute exceptions, limitations, or
conditions which conflict with the clearly expressed legislative intent.
Blair, 215 Ill. 2d at 443. If the plain language reveals legislative
intent, we will give that intent effect without resorting to other
interpretive aids. People v. Roberts, 214 Ill. 2d 106, 116 (2005).
    We find that the drugged condition alleged hereBan unexpected
adverse side effect of a prescription drug that was unwarned by the
prescribing doctor, the PDR or the package insertBis Ainvoluntarily
produced@ within the plain meaning of the involuntary intoxication
affirmative defense statute. In the absence of a specific definition of
the word Ainvoluntarily,@ we assume that the legislature intended the
word to have its ordinary and popularly understood meaning. People
v. Ward, 215 Ill. 2d 317, 325 (2005). Webster=s Third New
International Dictionary defines Ainvoluntary@ as Aspringing from
accident or impulse rather than conscious exercise of the will.@
Webster=s Third New International Dictionary 1191 (1993). Black=s
Law Dictionary defines Ainvoluntary@ as A[n]ot resulting from a free
and unrestrained choice; not subject to control by the will.@ Black=s
Law Dictionary 833 (7th ed. 1999). We note that the State ignores the
dictionary definition of Ainvoluntarily,@ and makes no argument
thereto. Further, we reject the State=s argument that the phrase
Ainvoluntarily produced@ requires further definition in the Code. An
unexpected and unwarned adverse effect of a drug taken on doctor=s
orders falls within the ordinary and popularly understood definition
of Ainvoluntarily.@ Thus, the unexpected and unwarned adverse effect
is not a conscious effect of a defendant=s will, is not resulting from a
defendant=s free and unrestrained choice, and is not subject to control
of defendant=s will.
    We additionally reject the State=s citation of several decisions of
our appellate court, claiming they support the restriction of the plain
meaning of Ainvoluntarily produced@ to trick, artifice, or force. The
overly restrictive interpretation underlying those courts= denial of an
involuntary intoxication instruction may be due to their
distinguishable facts. The cases did not determine whether the phrase
Ainvoluntarily produced@ encompassed, as here, a defendant=s adverse
drugged condition resulting from the ingestion of drugs according to

                                 -13-
doctor=s orders. People v. Downey, 162 Ill. App. 3d 322, 335 (1987)
(defendant claimed his action was involuntary because he was
addicted to cocaine); People v. Gerrior, 155 Ill. App. 3d 949, 953
(1987) (defendant knew the nature of the medicines and Antabuse he
was taking and was told by his physician of a potential extreme
reaction when taken with alcohol); People v. Larry, 144 Ill. App. 3d
669, 677-78 (1986) (defendant smoked marijuana which he saw
another person put white powder on); People v. Walker, 33 Ill. App.
3d 681, 688 (1975) (defendant received pills containing Seconal from
his brother and consumed alcohol). Each of those situations lacked
the kind of Aexternal influence@ on the cause of a defendant=s drugged
condition that defendant=s evidence propounded here. In each of those
cases, the defendant=s drugged condition was a result of the
defendant=s conscious choice.
    Further, the standard utilized by those cases derives from the
predecessor statute to the one at issue here. Walker, 33 Ill. App. 3d at
688, quoting People v. Bartholomew, 104 Ill. 601, 606 (1882),
quoting Ill. Rev. Stat. 1874, ch. 38, par. 291 (ADrunkeness shall not
be an excuse for any crime or misdemeanor, unless such drunkeness
be occasioned by the fraud, contrivance or force of some other
person, for the purpose of causing the perpetration of an offense@);
Larry, 144 Ill. App. 3d at 676-77 (the A >trickery, fraud and deceit= @
standard was set forth in Walker which relied on Bartholomew which
set forth the predecessor statute).
    We note, however, that we have reached a contrary legal
conclusion in People v. Rogers, 123 Ill. 2d 487 (1988). In our one
paragraph consideration of this issue, we stated, AWe agree with the
appellate decisions indicating that the General Assembly, in using the
expression >involuntary intoxication,= was contemplating intoxication
induced by some external influence such as trick, artifice or force.@
Rogers, 123 Ill. 2d at 508. Nevertheless, our decision suffered from
the same infirmity as the appellate decisions of being derived from
the predecessor statute. Additionally, the intoxication in that case did
not result from adverse affects of drugs prescribed by a physician but
from a defendant=s multiple drug addiction. To the extent that Rogers,
Downey, Gerrior, Walker, and Larry can be read as excluding the
unexpected and unwarned adverse side effects from medication taken
on doctor=s orders from the plain meaning of Ainvoluntarily
produced,@ they are overruled.

                                 -14-
    We thus reject the State=s limited interpretation of the plain
meaning of Ainvoluntarily produced@ to trick, artifice, or force as too
narrow. While the State is correct that the phrase Ainvoluntarily
produced@ may also subsume the meaning of Afraud, contrivance or
force,@ there is nothing in the statute which dictates that it must be
limited to this meaning. It is never proper for a court to depart from
plain language by reading into the statute exceptions, limitations, or
conditions which conflict with the clearly expressed legislative intent.
Blair, 215 Ill. 2d at 443. We further do not address the State=s
argument as to the committee comments to the statute. Because we
find that the plain language of the statute reveals legislative intent, we
need not resort to other interpretive aids. Roberts, 214 Ill. 2d at 116.
    Turning to the matter at hand, the record reveals evidence
entitling defendant to an instruction pursuant to section 6B3 of the
Code (720 ILCS 5/6B3 (West 2002)). Involuntary intoxication is an
affirmative defense which would exculpate an accused if the trier of
fact believed that the elements of involuntary intoxication had been
proven. 720 ILCS 5/6B3, 6B4 (West 2002)). The Criminal Code of
1961 provides that an affirmative defense Ameans that unless the
State=s evidence raises the issue involving the alleged defense, the
defendant, to raise the issue, must present some evidence thereon.@
720 ILCS 5/3B2(a) (West 2002). If an affirmative defense is raised,
Athen the State must sustain the burden of proving the defendant
guilty beyond a reasonable doubt as to that issue together with all the
other elements of the offense.@ 720 ILCS 5/3B2(b) (West 2002).
    Here, the record reveals defendant raised the issue of involuntary
intoxication by presenting Asome evidence@ that his drugged
condition was involuntarily produced and deprived him of substantial
capacity either to appreciate the criminality of his conduct or to
conform his conduct to the requirements of the law. 720 ILCS 5/6B3
(West 2002). The most critical of this evidence was Dr. Mitrione=s
opinion testimony, to a reasonable degree of medical and psychiatric
certainty, that at the time of the shooting defendant suffered from
involuntary intoxication in the form of a drugged condition caused by
some combination of Zoloft and diphenhydramine, with his lack of
sleep and previous alcohol dependency as contributing factors. Dr.
Mitrione further opined to a reasonable degree of medical and
psychiatric certainty that defendant, as a result of this involuntary
intoxication, lacked the substantial capacity to appreciate the

                                  -15-
criminality of his acts or conform his conduct to the requirements of
the law. The jury had the right to accept or reject Dr. Mitrione=s
opinion in considering the validity of defendant=s affirmative defense.
Accordingly, the trial court erred in failing to instruct the jury on
involuntary intoxication.
     The State next argues that the failure to give a jury instruction
was harmless error not requiring reversal. The State points to
evidence in the record which it contends demonstrates overwhelming
evidence of defendant=s guilt of attempted first degree murder and
first degree murder. We disagree.
     This court has held that where there is some evidence to support
an affirmative defense instruction, the trial court=s refusal to instruct
the jury constitutes an abuse of discretion even if the evidence is
conflicting. People v. Jones, 175 Ill. 2d 126, 131-32 (1997). Very
slight evidence upon a given theory of a case will justify the giving of
an instruction. Jones, 175 Ill. 2d at 132. Furthermore, fundamental
fairness includes, among other things, seeing to it that certain basic
instructions, essential to a fair determination of the case by the jury,
are given. People v. Ogunsola, 87 Ill. 2d 216, 222 (1981). The failure
to inform the jury of the elements of a crime charged has been held to
be a grave and fundamental error. Ogunsola, 87 Ill. 2d at 222. AIn
essence, unless the evidence before the trial court is so clear and
convincing as to permit the court to find as a matter of law that there
is no affirmative defense, the issue of whether a defendant should be
relieved of criminal liability by reason of his affirmative defense
must be determined by the jury with proper instruction as to the
applicable law.@ Jones, 175 Ill. 2d at 132. When the evidence raises
the basis for the instruction, a trial court=s refusal results in a denial of
defendant=s due process and entitles a defendant to a new trial. Jones,
175 Ill. 2d at 134.
     Because the defense evidence raised the affirmative defense, the
State held the burden of proving the defendant guilty beyond a
reasonable doubt as to that issue together with all other elements of
the offense. 720 ILCS 5/3B2 (West 2002). Yet, no instruction was
given that addressed the defense evidence. The jury, therefore, was
not informed that the evidence presented by defendant could provide
a defense to murder and attempted murder. The jury also was not
informed that the prosecution had the burden of proving beyond a


                                   -16-
reasonable doubt that defendant was not involuntarily intoxicated.
This omission Aremoved from the jury=s consideration a disputed
issue essential to the determination of defendant=s guilt or innocence.@
Ogunsola, 87 Ill. 2d at 223. Ultimately, it was for the jury to weigh
the evidence in determining whether the defendant suffered
involuntary intoxication such that he lacked substantial capacity to
appreciate the criminality of his acts or conform his conduct to the
requirements of the law. The jury therefore lacked the necessary tools
to analyze the evidence fully and to reach a verdict based on those
facts. See Jones, 175 Ill. 2d at 134. Such an error is a denial of due
process and requires that defendant be granted a new trial. Jones, 175
Ill. 2d at 134.
     We find the State=s proffered cases regarding the instant issue,
failure to instruct on an affirmative defense, inapposite. First, People
v. Ward, 187 Ill. 2d 249 (1999), and People v. Johnson, 146 Ill. 2d
109 (1991), do not address the complete failure to instruct the jury on
an affirmative defense. In Ward, two instructions, one of which was
ambiguous, and one of which was crystal clear, were submitted on
the intent element of murder. Ward, 187 Ill. 2d at 265-66. We stated,
AReading both instructions together, as the jury was instructed to do,
the jury simply could not have convicted defendant of both murders
on a finding of fewer than all of the elements required for each
victim.@ Ward, 187 Ill. 2d at 266. Similarly, in Johnson, we found
that it was harmless error to give guilty but mentally ill instructions
which required that defendant be found to be sane by a
preponderance of evidence rather than requiring proof of defendant=s
sanity beyond a reasonable doubt. Johnson, 146 Ill. 2d at 136. The
defendant in Johnson was not prejudiced, as the erroneous instruction
made a guilty but mentally ill verdict easier to reach than a proper
instruction would have, yet the jury declined to reach that verdict.
Johnson, 146 Ill. 2d at 138. These cases, however, do not address the
present situation, namely, the complete lack of any instruction on an
element raised by the defense evidence.
     While the State=s additional citation of People v. Ward, 32 Ill. 2d
253 (1965), concerns the failure to instruct the jury on a defendant=s
affirmative defense, it is also readily distinguishable. There, we found
A[n]one of the evidence complained of is specified [by defendant], nor
is any one of the instructions objected to set forth in the brief.@
Further, there was Anothing@ in the record to support the defendant=s

                                 -17-
proffered affirmative defense of provocation. Ward, 32 Ill. 2d at 256.
Here, as stated, there is at least Asome evidence,@ in the form of Dr.
Mitrione=s testimony, to support defendant=s affirmative defense of
involuntary intoxication. Even very slight evidence upon a given
theory of a case will justify an instruction. People v. Jones, 175 Ill.
2d at 132.
    Because we find that defendant should have received an
instruction as to his affirmative defense of involuntary intoxication,
we therefore reverse and remand for a new trial on this basis.
    We next examine defendant=s remaining issues regarding the
testimony of Tracy Parker to determine if they are likely to recur on
remand. People v. Fuller, 205 Ill. 2d 308, 346 (2002) (on review,
once it is decided that a new trial is required, additional claims of
error may be addressed if they are likely to arise again in the course
of retrial). Defendant first argues that the State failed to correct Tracy
Parker=s testimony that his cooperation could not help him with his
upcoming federal sentencing. Of relevance is the following testimony
by Parker on cross-examination by defense counsel:
              AQ. You are also aware of the provision of the federal
         sentencing guidelines that allows the Court when you are
         sentenced to give a substantial departure downward if you
         cooperate with authorities in turning somebody else=s offense;
         right?
              A. Not when it deals with state cases, no.
              Q. Federal cases; right?
              A. Just federal cases, yes.
              Q. That=s correct. And you are pending sentencing in
         Federal Court shortly; aren=t you?
              A. Yes.
              Q. And through your understanding in the federal system
         you are aware that there is the potential for, Judge McCuskey
         down here in Federal Court when it comes for sentencing to
         say, hey, he is a good guy; he cooperated with authorities in
         turning a case for us in Ford County and get you a reduction
         in time; is that right?
              A. I was aware of that. You can get a departure from your
         sentence; it had to do with the federal sentences. I was told I

                                  -18-
         couldn=t get anything from the state case. It had nothing to do
         with me federally. So it can=t help me either way.@
    The day after the jury returned the verdicts against defendant, the
prosecuting State=s Attorney sent a letter to the assistant United States
Attorney handling Parker=s federal case. It said,
              AI=m writing to advise you that Tracy Parker was
         subpoenaed and testified in the captioned Ford Co. murder
         trial. Parker was helpful and cooperative and provided useful
         information in our successful prosecution of defendant. This
         will also confirm that I made no promises whatsoever to
         Parker, and he requested nothing in exchange for his
         cooperation. Notwithstanding this, I still wanted to make you
         aware of Parker=s assistance in our case.@
The supplemental record reveals that Parker subsequently requested a
downward sentencing departure based on his substantial assistance in
the present matter, noting the letter. This request was unsuccessful.
Here, defendant argues that the above facts demonstrate that Tracy
Parker lied concerning his hopes to receive a benefit for testifying at
the trial and that the prosecutor failed to disclose this letter.
    Given that defendant will receive a new trial, requiring Parker to
testify again, and defendant now has the letter in his possession and
may bring it to the attention of the jury, we find that this issue is not
likely to occur on remand. Thus, we need not address it further.
    Defendant next asserts that the trial court erred in limiting his
cross-examination of Parker about his hope to obtain good-time credit
on his state sentences. The record reveals many questions, objections,
and rulings by the trial court with regard to both Parker=s state and
federal sentencing. Because we find that this issue is likely to occur
on remand, we address it.
    We disagree with defendant on the underlying reading of the
record, rather than the legal import of the argument. The record
reveals that the court reserved rulings on counsel=s questioning of
Parker to circumstantially demonstrate the specific length of time
Parker could hope to be reduced from his sentences. The court,
however, did not prohibit defense counsel from inquiring generally
about the good-time credit he hoped to receive. The record shows the
following colloquy to be among the questions on this issue between
defense counsel and Parker:

                                 -19-
            AQ. On the State charges you said there was good time.
        Could you get on the State charges that are pending and that
        you are going to serve; is that right?
            A. My State and Federal times run concurrent.
            Q. But you can get good time on the state charges,
        likewise; can=t you?
            A. The same as everybody else, yes.
            Q. Un-huh. So if you cooperate and if you behave, you
        can expect a reduction in you are [sic] State charges or you
        are [sic] State sentence?
            A. I don=t know about reduction. Everybody does a
        certain amount of time, if you don=t get in trouble while you
        are in prison.
            Q. That=s my point. That=s correct?
            A. Exactly.
            Q. Okay, no further questions, Judge.
            COURT: Okay. Then I am going to rule on my reserved
        objections, and I am directing the jury to disregard the
        questions and answers about the 10 years and 150 months and
        their connection to whether or not he can obtain good time for
        testifying in this case. That=s all that=s stricken. You are
        ordered to disregard it.@
    The judge=s reference to A10 years@ concerns the sentence Parker
received for burglary in the year 2000; the A150 months@ referred to
his 2000 federal sentence for possession of a firearm. Although the
record is much less than a picture of clarity with regards to the
specific arguments and rulings on this issue, we find that as a whole,
the record reveals that defendant was able to conduct an adequate
cross-examination of Parker=s expectation of good-time credit.
Therefore, we agree with the appellate court that the record reveals
that the trial court did not improperly restrict Parker=s testimony
regarding good-time benefits on state charges. Rather, the trial court
limited questioning only as to the length of the sentences, which was
already before the jury, and of which defendant does not complain
before this court. Because we find that the record does not bear out
the basis of defendant=s argument, we find no error.
    Accordingly, we reverse defendant=s convictions for attempted

                                -20-
murder and first degree murder and remand for a new trial.

                            CONCLUSION
   For the foregoing reasons, the judgments of the appellate court
and circuit court are reversed, and the cause is remanded to the circuit
court for a new trial.

                                             Reversed and remanded.




                                 -21-
