232 F.3d 570 (7th Cir. 2000)
UNITED STATES OF AMERICA, Plaintiff-Appellee,v.WARREN E. CORNETT, Defendant-Appellant.
No. 00-2083
In the  United States Court of Appeals  For the Seventh Circuit
Argued October 3, 2000Decided November 13,  2000

Appeal from the United States District Court  for the Southern District of Indiana,  Indianapolis Division.  No. 199CR00100-001--Sarah Evans Barker, Chief  Judge.[Copyrighted Material Omitted]
Before Flaum, Chief Judge, and Coffey and  Rovner, Circuit Judges.
Flaum, Chief Judge.


1
Warren Cornett  appeals his conviction for possessing a  firearm after being convicted of a  felony, arguing that the prosecutor made  several comments during her closing  argument that deprived him of a fair  trial. Specifically, Cornett contends  that the prosecutor (1) misstated the  burden of proof when she said that, in  order to acquit Cornett, the jury must  find that certain witnesses lied, and (2)  vouched for the credibility of government  witnesses when she mentioned that police  officers take an oath to uphold the law.  We conclude that these comments, although  improper, did not deprive Cornett of a  fair trial. Accordingly, we affirm the  judgment of the district court.

I.
Background

2
A federal grand jury indicted Cornett on  one count of possession of a firearm by a  felon, 18 U.S.C. sec. 922(g)(1). At  trial, government witness Roger Gammon,  the Indianapolis police officer who  arrested Cornett, testified that he  observed Cornett seated in the driver's  seat of a car drinking a beer; Cornett  was double-parked and was accompanied by  one passenger, Nicole Pittman. Attempting  to discern whether Cornett was  intoxicated, Gammon walked to the car and  stood next to the driver's door. From  this position, said the officer, he saw  the grip and trigger of a handgun  protruding from a gap separating the two  front seats. Gammon asked if either  Cornett or Pittman had a gun permit and  both replied "no." According to Gammon,  Cornett said that "he had purchased the  handgun approximately three weeks  earlier." Gammon arrested both Cornett  and Pittman.


3
Another government witness, Paul Arkins,  an Indianapolis detective on special  assignment to the United States Bureau of  Alcohol, Tobacco and Firearms, testified  that Cornett told him a different story  about the gun. Six weeks after Cornett's  arrest, Detective Arkins interviewed  Cornett in jail and read him Officer  Gammon's arrest report. According to  Arkins, Cornett denied telling Officer  Gammon that he purchased the gun. Rather,  Cornett explained that "some other dude"  had been in the car "just before" Officer  Gammon arrived and had left the gun in  the back seat. Cornett told Arkins that,  after the other individual left, Cornett  picked up the gun and tucked it into the  front seat cushion.


4
Cornett called only one witness,  passenger Nicole Pittman. Contradicting  Officer Gammon, Pittman denied that she  or Cornett had been asked about gun  permits, and that Cornett had told  Officer Gammon that he had purchased the  gun. Additionally, Pittman testified that  she never noticed the gun while she was  in the car. On cross-examination, though,  Pittman admitted that she had been  smoking marijuana and drinking beer five  minutes prior to Officer Gammon's arrival  and that the radio was playing during the  encounter with Officer Gammon. Pittman  also testified that in the "couple of  hours" preceding the arrests the only  other person in the car had been her  mother.


5
In the defense's closing argument,  Cornett's attorney stressed the  inconsistencies between Pittman's and  Officer Gammon's testimony, suggesting  that the incident did not occur the way  Officer Gammon described


6
Maybe it wasn't like Officer Gammon  described. I don't believe that gun was  positioned the way he described it.


7
So let's look at his statement. Well,  it's a convenient way to stick my client  with this charge by saying, Well, hey, my  client admitted to it. My client admitted  to Officer Gammon, according to Officer  Gammon, my client says, "Yeah, that gun,  I don't have a permit for it. I bought it  from a guy a few weeks ago."


8
Is it reasonable to believe that my  client would say that to the police  officer at that time? I don't think so.


9
Additionally, defense counsel argued  there were holes in the government's  case, such as a lack of fingerprint  evidence and the absence of written or  audio records of Cornett's statements to  the police.


10
In her rebuttal, the Assistant United  States Attorney stated that prosecutors  and police officers take oaths to follow  the law and so do not "stick" people with  charges: "That's not what the job is of a  prosecutor. It's not what the job is of  law enforcement. We don't stick people  with charges. We take oaths. We have  responsibilities." The prosecutor briefly  addressed the burden of proof and  thenreturned to her "oath" argument


11
Law enforcement officers, in fact, if  you've ever seen an induction ceremony,  take an oath. They take an oath to uphold  the laws of the jurisdiction in which  they work.


12
Officer Gammon took an oath to uphold  the laws of the state of Indiana and the  Constitution of the United States of  America.


13
Detective Arkins took the same oath.


14
Defense counsel objected that the  prosecutor was improperly bolstering her  witnesses. The court agreed and  instructed the prosecutor to proceed to a  discussion of the evidence.


15
The prosecutor also argued that to find  Cornett not guilty the jury would have to  conclude that Officer Gammon, Detective  Arkins and Pittman had all lied on the  stand


16
. . . [I]f you are going to find Mr.  Cornett not guilty . . . you are going to  have to find that all three of them came  in here, took an oath, and lied to you.  And there is no other way to characterize  that. And so go back and talk about it,  but talk about it in that way. You'll  have to find that they lied to you.


17
At the end of her rebuttal, the  prosecutor returned to this argument


18
If you're going to find reasonable  doubt, you have to find it from what you  do have: From Officer Gammon's testimony,  Nicole Pittman's testimony, Detective  Arkins' testimony. You are going to have  to disregard what they've said. You are  going to have to find that they are lying  about the evidence that they presented to  you, if you are going to acquit Mr.  Cornett. It's really that black and  white.1


19
After closing arguments the judge  instructed the jury that the government  has the burden of proving the defendant's  guilt beyond a reasonable doubt, that  this burden remains on the government  throughout the case, and that the  defendant is never required to prove his  innocence or to produce any evidence at  all. The court also informed the jury  that they are to consider only the  evidence and that the closing arguments  are not evidence unless made as an  admission or stipulation of fact.  Finally, the court instructed the jury  that they are the sole judges of the wit  nesses' credibility, and that a law  enforcement officer's testimony is  neither more nor less entitled to belief  than any other witness.

II.
Discussion

20
To determine if a prosecutor's comments  deprived a defendant of a fair trial, we  must first decide whether "the comments,  looked at in isolation, were improper."  United States v. Cusimano, 148 F.3d 824,831 (7th Cir. 1998). If the remarks were  improper, we then "look at the remarks in  the light of the entire record to  determine whether the defendant was  deprived of a fair trial." Id. In  assessing the prejudicial nature of a  prosecutor's improper comments, we  consider five factors: (1) the nature and  seriousness of the comments; (2) whether  the defense counsel invited the  prosecutor's remarks; (3) whether the  trial court's instructions to the jury  were adequate to cure any prejudice that  might otherwise result from the improper  comments; (4) whether the defense was  able to counter the improper arguments  through rebuttal; and (5) the weight of  the evidence against the defendant. Id.  at 831-32.

A.  Burden of Proof

21
Cornett first argues that the prosecutor  misstated the burden of proof when she  told the jury that to acquit the  defendant they must find that several  witnesses lied. In United States v.  Vargas, 583 F.2d 380, 387 (7th Cir.  1978), we held that it is improper for a  prosecutor to argue that the jury must  find that a witness lied to acquit the  defendant. See also United States v.  Phillips, 527 F.2d 1021, 1023 (7th Cir.  1975) (improper for prosecutor to argue  that to acquit the jury must find that  government framed defendant). We have  revisited this issue several times since  Vargas, distinguishing cases where the  prosecutor did not explicitly argue that  the jury must find a witness lied in  order to acquit. See United States v.  Amerson, 185 F.3d 676, 687 (7th Cir.  1999) (not improper for prosecutor to  comment that "[y]ou simply cannot believe  the testimony of these police officers  and believe the defendant's testimony at  the same time" because comments did not  force jury to decide between acquitting  defendant and believing police officers);  United States v. Marshall, 75 F.3d 1097,  1107-08 (7th Cir. 1996) (not improper for  prosecutor to comment that jury should  acquit if it disbelieved FBI agent  because prosecutor did not state that  disbelieving FBI agent was the only way  to acquit); United States v. Hernandez,  865 F.2d 925, 929-30 (7th Cir. 1989)  (same). This case, however, cannot be  distinguished in a similar fashion. Here,  the prosecutor argued that the jury  "[would] have to find that [Officer  Gammon, Detective Arkins and Pittman] are  lying about the evidence that they  presented to you, if you are going to  acquit Mr. Cornett. It's really that  black and white." Viewed in isolation,  the prosecutor's remarks misstated the  burden of proof because the jury could  have believed that the witnesses told the  truth and yet still found that the  government had failed to prove Cornett's  guilt beyond a reasonable doubt. See  Vargas, 583 F.2d at 387. Therefore, the  prosecutor's comments were improper.  Next, we turn to whether these comments  deprived Cornett of a fair trial.


22
As noted above, we analyze several  factors when assessing the prejudicial  effect of a prosecutor's misstatement of  the law. Of these factors, we place  considerable emphasis on the curative  effect of jury instructions and the  weight of the evidence. See United States  v. Miller, 199 F.3d 416, 423 (7th Cir.  1999); United States v. Hauert, 40 F.3d  197, 205 (7th Cir. 1994); United States  v. Davis, 15 F.3d 1393, 1400-02 (7th Cir.  1994). Here, in its final charge to the  jury, the district court gave proper  instructions on the burden of proof and  directed the jury to disregard the  closing arguments to the extent they were  not supported by the evidence. Absent  evidence to the contrary, we presume that  the jury understood and followed the  district court's instructions. See United  States v. Nobles, 69 F.3d 172, 184 (7th  Cir. 1995). Regarding the weight of the  evidence, the government presented  uncontroverted proof that Cornett  possessed a firearm. Officer Gammon  testified that he recovered a gun from  Cornett's car, and both Officer Gammon  and Detective Arkins testified that  Cornett admitted possessing the firearm.  Pittman, Cornett's only witness, did not  contradict this evidence. Pittman's  testimony that she did not see the gun  tucked in the front seat cushion tends  only to establish that Pittman did not  personally observe the gun. Moreover,  Pittman's testimony is undercut by her  admission that she was smoking marijuana  and drinking beer five minutes before the  incident. And, finally, Cornett did not  introduce any evidence to dispute  Detective Arkins's testimony that Cornett  admitted possessing the firearm or to  attack Detective Arkins's credibility.


23
Moving to the remaining factors; first,  the prosecutor's improper comments were  clearly out of bounds. The prosecutor  spoke to an altering of the burden of  proof when she argued that the defendant  had to prove certain witnesses lied to be  acquitted. We also note that the  prosecutor's misstatement of the law was  not a brief and isolated comment; rather,  it was a repeated theme of her rebuttal  argument. Second, Cornett did not invite  the prosecutor's improper comments.  Third, because the prosecutor made the  challenged comments during rebuttal,  defense counsel did not have a chance to  respond. On the other hand, defense coun  sel never specifically objected to the  prosecutor's misstatement of the burden  of proof. Therefore, the court was not  presented with the opportunity to give  curative instructions, nor did the  prosecutor have the opportunity to  acknowledge her error to the jury and  amend her argument accordingly.


24
Generally, a prosecutor's improper  comments do not deprive a defendant of a  fair trial when the district court  properly instructs the jury and the  weight of the evidence is in the  government's favor. See Miller, 199 F.3d  at 422-23 (defendant not deprived of a  fair trial even though error was serious,  directed at the only contested issue at  trial and defendant had no opportunity to  respond); United States v. Morgan, 113  F.3d 85, 90-91 (7th Cir. 1997) (defendant  not deprived of a fair trial even though  comments not invited and defendant did  not have an opportunity to respond);  United States v. Badger, 983 F.2d 1443,  1456 (7th Cir. 1993) (same). This case  provides no reason to depart from this  approach. Given the court's instructions  and the weight of the evidence, we cannot  find any indication that the jury would  have returned a different verdict absent  the prosecutor's misstatement of the law.

B.  Improper Vouching

25
Cornett also argues that the prosecutor  improperly vouched for the good faith of  police witnesses when she stated that  police officers take an oath to follow  the law.2 Improper vouching occurs  when a prosecutor expresses her personal  opinion about the truthfulness of a  witness or when she implies that facts  not before the jury lend a witness  credibility. See United States v.  Renteria, 106 F.3d 765, 767 (7th Cir.  1997). The government argues that the  prosecutor's remarks about the police  officers' oaths were similar to  commenting that they were "good cops," a  comment we found permissible in United  States v. Alexander, 163 F.3d 426, 429  (7th Cir. 1998). In Alexander, however,  we noted that the "good cops" comment  came only after the prosecutor compared  one police officer's testimony to another  police officer's report to show that they  were consistent. See id. In this case,  there is no similar connection to the  evidence. Here, the prosecutor simply  bolstered the credibility of the police  officers by commenting on their  occupational integrity. Although we do  not find a case directly on point, we  have generally held that it is improper  for a prosecutor to vouch for the  credibility of witnesses by referring to  facts outside the record. See United  States v. Johnson-Dix, 54 F.3d 1295,  1304-05 (7th Cir. 1995) (improper to  state that police officer has no reason  to risk his career and reputation by  lying); United States v. Boyd, 54 F.3d  868, 871 (D.C. Cir. 1995) (same). The  Assistant United States Attorney also  invoked her own oath as a prosecutor,  thus implying that she would not present  perjured testimony to the jury and  further bolstering the officers'  credibility. This was improper as well.  See United States v. Torres, 809 F.2d  429, 446 (7th Cir. 1987) (Flaum, J.,  concurring). Given the prosecutor's  remarks, we examine whether they deprived  Cornett of a fair trial.


26
As noted above, we focus on the jury  instructions and the weight of the  evidence when assessing the prejudicial  nature of a prosecutor's improper  comments. Here the district court's  instructions effectively addressed any  prejudice that might otherwise have  resulted from the improper vouching. The  court instructed the jury that they were  the "sole judges of the credibility of  the witnesses" and that a police  officer's testimony "is neither more nor  less entitled to belief than any other  witness." As previously stated, the  weight of the evidence favors the  government. Cornett has argued that the  government's case depended on the  credibility of Officer Gammon and  Detective Arkins, the two witnesses for  whom the prosecutor improperly vouched.  Since there was no indication that the  credibility of these officers was ever in  serious doubt, the improper vouching was  harmless. Pittman's testimony constituted  only a weak attack on Officer Gammon's  version of events, and the defense never  questioned Detective Arkins's  credibility.


27
Overall, an examination of the record  does not suggest the conclusion that the  prosecutor's comments prejudiced the  defendant. The comments, while improper,  were not critical to the outcome of the  case. Although the prosecutor did vouch  for witnesses central to the government's  case, the prosecutor never stated that  she personally believed the police  officers. Furthermore, the district court  sustained a defense objection, thus  signaling to the jury that the thrust of  the prosecutor's remarks was improper.  Additionally, the prosecutor's comments  were in response to defense counsel's  suggestion that Officer Gammon and the  prosecution were trying to "stick"  Cornett with a conviction. Finally,  although the prosecutor twice vouched for  the police officers' credibility during  her rebuttal argument, this circumstance,  standing alone, cannot establish that the  prosecutor's comments deprived the  defendant of a fair trial. See Johnson-  Dix, 54 F.3d at 1305 (prosecutor's  vouching for a witness's credibility  during rebuttal argument did not deprive  defendant of a fair trial because weight  of the evidence was against the  defendant); see also Davis, 15 F.3d at  1401-02 (reasoning that district court's  instruction that jurors are sole judges  of witness credibility "effectively  addressed the risk the vouching presented  and sufficiently dispelled any  prejudicial effect the vouching may have  had").

III.
Conclusion

28
The prosecutor misstated the burden of  proof and improperly vouched for the  credibility of government witnesses.  However, the court concludes that these  remarks did not deprive Cornett of a fair  trial. Therefore, the judgment of the  district court is AFFIRMED.



Notes:


1
 Although it appears that Cornett objected only to  the prosecutor's improper vouching and not to her  misstatement of the burden of proof, we will  assume for purposes of analysis that Cornett  objected to both comments. Because we conclude  that neither comment deprived Cornett of a fair  trial, whether Cornett objected to both comments  is not determinative.


2
 The government frames this issue as whether the  prosecutor's "reminder" that the witnesses took  an oath was improper. This assertion misreads the  nature of the objection. The remarks objected to  by the defense did not refer to the oath witness-  es take before testifying, which is the only oath  this jury could have been aware of from the  evidence adduced at trial. Rather, the defense  objected when the prosecutor commented that, upon  becoming police officers, Officer Gammon and  Detective Arkins took an oath to uphold the law.  Because no evidence of this oath of office was  introduced at trial, it is inaccurate to charac-  terize the prosecutor's comments as a "reminder."


