Opinion
KATZ, J.
The defendant, Balbir Singh, appeals, pursuant to our grant of certification, from the judgment of the Appellate Court affirming the trial court’s judgment of conviction, rendered after a jury trial, of two counts of arson in the first degree in violation of General Stat[695]*695utes § 53a-lll (a) (1) and (4).1 The sole issue in this appeal is whether the state’s attorney’s cross-examination of the defendant and his closing argument to the jury deprived the defendant of a fair trial in violation of his federal constitutional rights.2 We reverse the judgment of the Appellate Court.
The opinion of the Appellate Court sets forth the following facts that the jury reasonably could have found. “Beginning in December, 1994, the defendant rented the first two floors of 1195 Chapel Street in New Haven, the basement of which housed the defendant’s Prince Restaurant. The [upper two] floors of the building contained apartments occupied by college students. The defendant’s lease was to run until October 31,1999, but was terminable in the event that the premises were destroyed by fire or explosion. The defendant was experiencing financial difficulty with his restaurant business. In 1995, he had missed [making] some rent payments and needed to take a $10,000 loan to pay his employees. In February, 1996, the defendant admitted that his business was not ‘particularly good’ and ‘just pretty much shaky.’ By the spring of 1996, the defendant was driving a [taxicab] because his restaurant business was not doing well enough to meet his debts.
“On July 6, 1996, the night of the incident at issue, the doorman at the defendant’s apartment complex observed the defendant and his father enter the lobby at about 11 p.m., which comported with their usual [696]*696routine. The doorman found it unusual, however, that the defendant approached him and asked him for the time, despite the fact that there was a large clock on the wall. The doorman also noticed while he was speaking with the defendant, that the defendant appeared to be looking at the security monitors, which cover four of the six entrances to the building.
“At about midnight on July 7, 1996, Christopher Gansen, a student who lived near the Prince Restaurant, was walking home and saw a man of Asian-Indian descent who appeared to be agitated and nervous. The man crossed the street in front of Gansen, having come from the vicinity of the Prince Restaurant. According to Gansen, the streetlighting was adequate and allowed him to see the man’s facial features.
“At [12:17] a.m. on July 7, 1996, firefighters from the New Haven fire department arrived at 1195 Chapel Street to find black smoke coming from the building. The firefighters gained entry by forcing a locked rear door and by smashing open a rear glass door. After putting out the fire in the basement, the firefighters forced open the front door and broke open the first floor windows of the building to examine the first floor.
“At 1:30 a.m., Frank Dellamura, a fire investigator in the office of the New Haven fire marshal, arrived and interviewed firefighters and examined the building. [There was no one in the building.] He observed that the doors and windows of the building had been forced or smashed in, and confirmed from firefighters on the scene that they were responsible for the broken windows and the forced doors.
“Dellamura noted the black smoke, which suggested that an accelerant had been used to start the fire. On the basis of bum patterns and other physical evidence, [he] concluded that the fire had started in the basement. . . . Dellamura also detected a noticeable gasoline [697]*697odor . . . .” State v. Singh, 59 Conn. App. 638, 640-41, 757 A.2d 1175 (2000). He then brought some of the debris from the floor of the building outside to the parking lot where a state trooper and Louise, a state police canine that had been trained to detect petroleum based products, were located. Louise alerted to each of the items brought out by Dellamura, indicating the presence of such a petroleum based product.3 Dellamura also discovered that the fire alarm panel on the floor above the basement had been tampered with so that it had been disconnected from its battery backup power. He concluded that the fire had been intentionally set. Joseph Pettola, a member of the fire investigation unit of the New Haven police department, interviewed Gansen at the fire scene and obtained a description of the man he saw leaving the vicinity of the Prince Restaurant.
“On July 7, 1996, Dellamura and [Pettola] . . . visited the defendant at his apartment, which was two blocks from the fire scene. [They] informed the defendant that there had been a fire in his restaurant. Before the two men told the defendant that arson was suspected, the defendant became hysterical, exclaiming that the fire had been set by a former restaurant employee who had been fired the previous week.4 The defendant claimed that he and his father had left the restaurant at 11 p.m. the previous night and that [thereafter] he had remained in his apartment all night.” Id., 641-42.
The defendant, visibly anxious to go to the restaurant, began to leave his apartment while still wearing his sandals. “Dellamura suggested that because of the [698]*698messy nature of the fire scene, the defendant should instead wear shoes. The defendant ignored Dellamura’s suggestion and wore [his] sandals to the scene of the fire. The property manager of the building [Gary Dingus], who also was inspecting the fire scene, noticed that the defendant was wearing sandals at the scene of the fire.
“On July 8, 1996, Dellamura and Pettola returned to the defendant’s apartment [along with a police detective and the police canine Louise]. After the defendant consented to a search of his apartment, [Louise] alerted the police to a pair of black loafers in a closet. Tests later confirmed the presence of gasoline on the loafers. The defendant admitted to owning the shoes [but] claimed that they must have been contaminated by gasoline when he wore them to inspect the fire scene the previous day with the investigators. The investigators, however, recalled that the defendant had worn sandals when he visited the fire scene.
“On July 16, 1996, Dellamura and Pettola visited the apartment of Gansen, the student who had seen an Asian-Indian man in the vicinity of the Prince Restaurant on the night of the fire. Gansen was shown an array of six photographs of Asian-Indian males. He instantly recognized the defendant as the man he had seen on the night of the fire at about 12 a.m. and subsequently made an in-court identification of the defendant.” Id., 642-43.
The jury returned guilty verdicts on two counts of arson in the first degree in violation of § 53a-111 (a) (1) and (4).5 Thereafter, the trial court sentenced the defendant to a total effective term of twenty-five years [699]*699imprisonment, execution suspended after ten years, and five years probation. The defendant appealed from the judgment of conviction to the Appellate Court, claiming, inter alia,6 that prosecutorial misconduct during the course of cross-examination and closing argument deprived him of a fair trial. The Appellate Court concluded that the state’s attorney’s conduct was not improper and affirmed the judgment of conviction. Id., 649, 654. This appeal followed. Additional facts will be set forth as necessary.
Because the defendant failed to object to the alleged prosecutorial misconduct at trial, he may prevail only if he satisfies all four requirements of State v. Golding, 213 Conn. 233, 239-40, 567 A.2d 823 (1989).7 We conclude that he has satisfied all four prongs of Golding.
“To prove prosecutorial misconduct, the defendant must demonstrate substantial prejudice. State v. Richardson, 214 Conn. 752, 760, 574 A.2d 182 (1990); State v. Northrop, 213 Conn. 405, 421, 568 A.2d 439 (1990). In [700]*700order to demonstrate this, the defendant must establish that the trial as a whole was fundamentally unfair and that the misconduct so infected the trial with unfairness as to make the conviction a denial of due process. Darden v. Wainwright, 477 U.S. 168, 181, 106 S. Ct. 2464, 91 L. Ed. 2d 144 (1986) . . . .” (Citation omitted.) State v. Alexander, 254 Conn. 290, 303, 755 A.2d 868 (2000).
“Prosecutorial misconduct may occur in the course of cross-examination of witnesses; State v. Hafner, 168 Conn. 230, 249, 362 A.2d 925, cert. denied, 423 U.S. 851, 96 S. Ct. 95, 46 L. Ed. 2d 74 (1975); and may be so clearly inflammatory as to be incapable of correction by action of the court. Id., 252-53. In such instances there is a reasonable possibility that the improprieties in the cross-examination either contributed to the jury’s verdict of guilty or, negatively, foreclosed the jury from ever considering the possibility of acquittal. Id., 253.” (Internal quotation marks omitted.) State v. Williams, 204 Conn. 523, 538-39, 529 A.2d 653 (1987). Moreover, “prosecutorial misconduct of constitutional proportions may arise during the course of closing argument, thereby implicating the fundamental fairness of the trial itself . . . .” (Internal quotation marks omitted.) State v. Burton, 258 Conn. 153, 165, 778 A.2d 955 (2001).
“In determining whether prosecutorial misconduct was so serious as to amount to a denial of due process, this court, in conformity with courts in other jurisdictions, has focused on several factors. . . . Included among those factors are the extent to which the misconduct was invited by defense conduct or argument; State v. Falcone, 191 Conn. 12, 23, 463 A.2d 558 (1983); the severity of the misconduct; see United States v. Modica, 663 F.2d 1173, 1181 (2d Cir. 1981), cert. denied, 456 U.S. 989, 102 S. Ct. 2269, 73 L. Ed. 2d 1284 (1982); the frequency of the misconduct; State v. Couture, 194 Conn. 530, 562-63, 482 A.2d 300 (1984), cert. denied, [701]*701469 U.S. 1192, 105 S. Ct. 967, 83 L. Ed. 2d 971 (1985) . . . the centrality of the misconduct to the critical issues in the case; Hawthorne v. United States, 476 A.2d 164, 172 (D.C. App. 1984); the strength of the curative measures adopted; United States v. Modica, supra, 1181 . . . and the strength of the state’s case. See [id.] . . . .” (Citations omitted; internal quotation marks omitted.) State v. Whipper, 258 Conn. 229, 262-63, 780 A.2d 53 (2001).
As is evident upon review of these factors, it is not the prosecutor’s conduct alone that guides our inquiry, but, rather, the fairness of the trial as a whole. Smith v. Phillips, 455 U.S. 209, 219, 102 S. Ct. 940, 71 L. Ed. 2d 78 (1982); State v. Alexander, supra, 254 Conn. 303. We are mindful throughout this inquiry, however, of the unique responsibilities of the prosecutor in our judicial system. A prosecutor “is not only an officer of the court, like every other attorney, but is also a high public officer, representing the people of the State, who seek impartial justice for the guilty as much as for the innocent. ... By reason of his [or her] office, [the prosecutor] usually exercises great influence upon jurors. [The prosecutor’s] conduct and language in the trial of cases in which human life or liberty are at stake should be forceful, but fair, because he [or she] represents the public interest, which demands no victim and asks no conviction through the aid of passion, prejudice or resentment. If the accused be guilty, he [or she] should none the less be convicted only after a fair trial, conducted strictly according to the sound and well-established rules which the laws prescribe. While the privilege of counsel in addressing the jury should not be too closely narrowed or unduly hampered, it must never be used as a license to state, or to comment upon, or to suggest an inference from, facts not in evidence, or to present matters which the jury have no right to [702]*702consider.” (Internal quotation marks omitted.) State v. Alexander, supra, 302.
The defendant’s claims of prosecutorial misconduct fall within four categories of proscribed conduct: (1) questions and comments on the veracity of other witnesses’ testimony; (2) personal expressions of opinion on evidence; (3) references to matters not in evidence; and (4) appeals to the emotions, passions and prejudices of the jurors. The defendant does not claim that any one category of conduct alone is a sufficient basis for reversal. We therefore address each in turn to determine whether the particular conduct was improper before determining whether the impropriety, if any, deprived the defendant of a fair trial.
I
The defendant first contends that during cross-examination the state’s attorney improperly compelled him to characterize the testimony of other witnesses, and then improperly emphasized that testimony in closing argument. The following additional facts are relevant to our analysis.
The prosecution’s theory of the case was that the defendant had committed arson because of his financial difficulties. In support of this theory, the state offered two witnesses who testified that the defendant had told them that his business was “slow” and “[not] particularly good . . . just pretty much shaky.” A third witness, Joel Young, a partner in the business that held the defendant’s lease, testified that the defendant had failed to pay his May, 1995 rent. When the defendant disputed that he had made those statements, the state’s attorney asked the defendant whether the testimony was incorrect or made up, or wrong.8 In addition, the [703]*703state offered the testimony of Naresh Komal, a businessman from the Asian-Indian community, who testified that he had loaned the defendant $10,000 and that the defendant had paid back only $6000. When the defendant testified on cross-examination that he had paid back the entire loan, the state’s attorney asked: “So is it your claim that Mr. Komal came into court and lied when he said that you still owed him over $4000 of that $10,000?” The defendant responded, “Yes.”
The sole piece of physical evidence linking the defendant to the crime scene was a pair of the defendant’s shoes, which tested positive for the presence of a petroleum based product consistent with gasoline. The defendant contended that the shoes had gasoline on them because he wore them regularly when filling his taxicab tank with gasoline and that he had, in fact, worn the shoes to fill the tank just hours before the police seized the shoes.9 On cross-examination, the state’s attorney questioned the defendant as follows:
[704]*704“Q. It is your testimony here, is it not, that you were not present when the dog alerted to your shoes, right?
“A. I was in the apartment.
“Q. But you didn’t see it happen?
“A. No.
“Q. And you recall that’s different than what the people who were handling the dog said and [w]hat the detective said, right? Do you recall that’s different than what they testified to?
“A. Yes.
“Q. And are they lying about that? You shrugged your shoulders. Does that mean I don’t know?
“A. I don’t know.
“Q. In fact, when you saw the dog alert to them and they said the dog has said there is some kind of flammable [liquid] on those shoes you immediately said ‘I wore those shoes to the restaurant after I talked to you last night,’ didn’t you? Yes or no? Did you understand the question?
“A. No. . . .10
“Q. The police told you they believed there was some kind of flammable liquid on your shoe[s]?
“A. They don’t tell me nothing. . . .
“Q. Did they tell you why they wanted to seize your shoes?
[705]*705“A. Because I gave them the shirt, my pants and they said the dog—they told me the dog pointed [to these] shoes, we have to take it. I said no problem, take it.
“Q. So when they testified that in fact they informed you that they believed there was gasoline on the shoes, they were wrong or lying, correct?11
“A. They told me they want to take shoes. I say okay.”
In his closing argument, the state’s attorney continued to underscore his view of the defendant’s characterization of these witnesses and Gansen when he identified the defendant as the man he had seen near the crime scene: “What does [the defendant] tell you? He insists on telling you that he’s telling the truth. At the most damaging point in his testimony, he remembers all these details about that night but he [forgets] exactly what he said when the dog alerts [to] his shoe. And why does he have to tell you that? He has to tell you that he doesn’t remember it because otherwise he has to directly call Pettola and Dellamura liars when they tell you . . . what [the defendant] does [when] the dog alerts on the shoes in his presence, they told him what the dog—what that means and [the defendant] says T wore these back to the scene.’
íjc í{í
“So everyone else lies. [Gansen] lies, Dellamura, Pettola, Komal, Dingus [the property manager] they all [706]*706must be lying because you’re supposed to believe this defendant, this defendant who is the only person who continually tells you and almost always at key moments in the testimony when there is some question that is . . . hard to answer . . . without looking like [he is] guilty, that is when he said ‘I’m telling the truth’ ....
* * *
“Again, remember that if you buy the argument that [Gansen] couldn’t have done it, couldn’t have seen what he says he saw, then you have to conclude that [Gansen] lied.”
We previously have not had the opportunity to address the well established evidentiary rule that it is improper to ask a witness to comment on another witness’ veracity. See, e.g., United States v. Sanchez, 176 F.3d 1214, 1219-20 (9th Cir. 1999); United States v. Gaines, 170 F.3d 72, 81 (1st Cir. 1999); United States v. Lin, 101 F.3d 760, 769 (D.C. Cir. 1996); United States v. Scanio, 900 F.2d 485, 493 (2d Cir. 1990); Knowles v. State, 632 So. 2d 62, 65-66 (Fla. 1993); People v. Riley, 63 Ill. App. 3d 176, 184-85, 379 N.E.2d 746 (1978); State v. Manning, 270 Kan. 674, 19 P.3d 84, 103 (2001); Commonwealth v. Martinez, 431 Mass. 168, 177, 726 N.E.2d 913 (2000); State v. Flanagan, 111 N.M. 93, 97, 801 P.2d 675 (App. 1990); Burgess v. State, 329 S.C. 88, 91, 495 S.E.2d 445 (1998); State v. Emmett, 839 P.2d 781, 787 (Utah 1992); State v. Casteneda-Perez, 61 Wash. App. 354, 362, 810 P.2d 74 (1991).12 A few of these courts have drawn a distinction between using the words “wrong” or “mistaken” rather than “lying” in questions and closing arguments, concluding that the former [707]*707terms are not improper because they merely “ [highlight] the objective conflict without requiring the witness to condemn the prior witness as a purveyor of deliberate falsehood, i.e., a ‘liar.’ ” United States v. Gaind, 31 F.3d 73, 77 (2d Cir. 1994); see also United States v. Gaines, supra, 82 (use of word “wrong” proper in present case but court declines to address whether it would be in all instances); but see State v. Flanagan, supra, 97 (asking if another witness is mistaken is improper because it “may amount to simply argument to the jury, in which the prosecutor improperly suggests that the only possible alternatives are that either the defendant or the witness is a liar”).
Several reasons underlie the prohibition on such questions. First, it is well established that “determinations of credibility are for the jury, and not for witnesses.” (Internal quotation marks omitted.) United States v. Lin, supra, 101 F.3d 769; United States v. Forrester, 60 F.3d 52, 63 (2d Cir. 1995) (“[a]s a matter of law, ‘[t]he credibility of witnesses is exclusively for the determination by the jury, and witnesses may not opine as to the credibility of the testimony of other witnesses at the trial’ ”); United States v. Akitoye, 923 F.2d 221, 224 (1st Cir. 1991) (“it is not the place of one witness to draw conclusions about, or cast aspersions upon, another witness’ veracity”); State v. Aponte, 249 Conn. 735, 756, 738 A.2d 117 (1999) (credibility of witnesses is within exclusive purview of jury). Consequently, questions that ask a defendant to comment on another witness’ veracity invade the province of the jury. United States v. Gaines, supra, 170 F.3d 81; State v. Manning, supra, 19 P.3d 103; State v. Casteneda-Perez, supra, 61 Wash. App. 362; see also State v. Schleifer, 102 Conn. 708, 724, 130 A. 184 (1925) (“[i]t is never permissible, though often done, to ask a witness to characterize the testimony or statement of another witness”). Moreover, “[a]s a general rule, [such] ques[708]*708tions have no probative value and are improper and argumentative because they do nothing to assist the jury in assessing witness credibility in its fact-finding mission and in determining the ultimate issue of guilt or innocence.” State v. Pilot, 595 N.W.2d 511, 518 (Minn. 1999); accord Commonwealth v. Ward, 15 Mass. App. 400, 401, 446 N.E.2d 89 (1983) (improperio ask question designed to cause one witness to characterize another’s testimony as lying); State v. Flanagan, supra, 111 N.M. 97 (same); State v. Emmett, supra, 839 P.2d 787 (question to defendant of whether victim lied in testimony improper because it sought information beyond defendant’s competence).
Second, questions of this sort also create the risk that the jury may conclude that, in order to acquit the defendant, it must find that the witness has lied. State v. Casteneda-Perez, supra, 61 Wash. App. 362; see also State v. Flanagan, supra, 111 N.M. 97 (questions may mislead jury that only alternative is that defendant or witness is lying). This risk is especially acute when the witness is a government agent in a criminal case. United States v. Fernandez, 145 F.3d 59, 64 (1st Cir. 1998) (finding it unfair to force witness to choose between recanting own testimony and calling law enforcement officer a liar “[gjiven the faith the jury may place in the word of a law enforcement officer”); United States v. Weiss, 930 F.2d 185, 195 (2d Cir.), cert. denied, 502 U.S. 842, 112 S. Ct. 133, 116 L. Ed. 2d 100 (1991) (explaining that special concern may be warranted in such cases because some people may believe that government agent has “heightened credibility”); Commonwealth v. Ward, supra, 15 Mass. App. 402 (same). A witness’ testimony, however, “can be unconvincing or wholly or partially incorrect for a number of reasons without any deliberate misrepresentation being involved”; State v. Casteneda-Perez, supra, 363; such as “misrecollection, failure of recollection or other innocent reason.” United [709]*709States v. Narciso, 446 F. Sup. 252, 321 (E.D. Mich. 1977); see also State v. Emmett, supra, 839 P.2d 787 (question regarding victim’s veracity prejudicial because it suggests that “witness is committing perjury even though there are other explanations for the inconsistency . . . [and] puts the defendant in the untenable position of commenting on the character and motivations of another witness who may appear sympathetic to the jury”).
Similarly, courts have long admonished prosecutors to avoid statements to the effect that if the defendant is innocent, the jury must conclude that witnesses have lied.13 United States v. Richter, 826 F.2d 206, 208 (2d Cir. 1987); United States v. Reed, 724 F.2d 677, 681 (8th Cir. 1984); United States v. Nwankwo, 2 F. Sup. 2d 765, 769 (D. Md. 1998); State v. Williams, 41 Conn. App. 180, 184-85, 674 A.2d 1372, cert. denied, 237 Conn. 925, 677 A.2d 950 (1996); see also United States v. Cornett, 232 F.3d 570, 574 (7th Cir. 2000) (limiting this rule to arguments in which express, direct link is made between acquittal and conclusion that witnesses lied). The reason for this restriction is that “[t]his form of argument . . . involves a distortion of the government’s burden of proof.” United States v. Reed, supra, 681; accord United States v. Vargas, 583 F.2d 380, 387 (7th Cir. 1978) (noting that such comments excluded possibility that jury could have concluded only that witnesses were probably truthful and defendant was probably lying, thereby preventing jury from “return [ing] a verdict of not guilty because the evidence might not be sufficient to convict the defendant beyond [710]*710a reasonable doubt”); United States v. Nwankwo, supra, 769 (same). Moreover, like the problem inherent in asking a defendant to comment on the veracity of another witness, such arguments preclude the possibility that the witness’ testimony conflicts with that of the defendant for a reason other than deceit. Cf. United States v. Narciso, supra, 446 F. Sup. 321; State v. Emmett, supra, 839 P.2d 787.
In the present case, the state’s attorney’s argument stated, in essence, that the only way the jury could conclude that the defendant had not set the fire was if it determined that five government witnesses had lied. Moreover, the state’s attorney particularly emphasized this argument with respect to Gansen’s identification by expressing his own personal belief that the jury had in fact concluded that Gansen had not lied.14
The state recognizes these rules but asks this court to adopt the minority position, which the Appellate Court applied. That position provides an exception to the prohibition of questions and comments on witnesses’ veracity when the defendant’s testimony “is the opposite of or contradicts the testimony of other witnesses,” thereby presenting a “basic issue of credibility . . . [that cannot] be attributed to defects or mistakes in a prior witness’ perception or inaccuracy of memory, rather than to lying.” (Emphasis added.) State v. Singh, supra, 59 Conn. App. 645; accord State v. Morales, 198 Ariz. 372, 375, 10 P.3d 632 (App. 2000); State v. Pilot, [711]*711supra, 595 N.W.2d 518; State v. Hart, 303 Mont. 71, 80-81, 15 P.3d 917 (2000); People v. Overlee, 236 App. Div. 2d 133, 139, 666 N.Y.S.2d 572 (1997). The state contends that such an exception is permissible because, under these circumstances, the jury’s role is not usurped because it still must decide ultimately which testimony to believe. This argument fails to demonstrate, however, why an exception to the rule is neces sary. The state’s objective of “highlighting” inconsistencies in testimony may be accomplished by other, proper means. Moreover, we reject this exception because, as we previously have emphasized, testimony may be in direct conflict for reasons other than a witness’ intent to deceive. United States v. Narciso, supra, 446 F. Sup. 321; State v. Casteneda-Perez, supra, 61 Wash. App. 363. It would be unwise, in our view, to make the application of this exception predicated on such a difficult distinction, which is relegated properly to the jury.15
[712]*712Therefore, we reject the state’s invitation to carve out an exception to the rule that a witness may not be asked to characterize another witness’ testimony as a he, mistaken or wrong.16 Moreover, closing arguments providing, in essence, that in order to find the defendant not guilty, the jury must find that witnesses had lied, are similarly improper.17 Because the state’s attorney’s conduct in this case fell within these prohibited categories, we conclude that his questions and comments were improper.
II
We next address the defendant’s claim that the state’s attorney improperly expressed his personal views during closing arguments, in essence serving as an unsworn witness in support of those views. It is well settled that, “in addressing the jury, [cjounsel must be allowed a generous latitude in argument, as the limits of legitimate argument and fair comment cannot be determined precisely by rule and line, and something must be allowed for the zeal of counsel in the heat of the argument.” (Internal quotation marks omitted.) State v. Robinson, 227 Conn. 711, 746, 631 A.2d 288 (1993); accord State v. Brown, 256 Conn. 291, 309-10, 772 A.2d 1107 (2001). Moreover, “[i]t does not follow . . . that every use of rhetorical language or device is improper. . . . The occasional use of rhetorical devices is simply fair argument.” (Internal quotation marks omitted.) State v. Brown, supra, 310.
[713]*713“The parameters of the term zealous advocacy are also well settled. The prosecutor may not express his own opinion, directly or indirectly, as to the credibility of the witnesses. . . . Nor should a prosecutor express his opinion, directly or indirectly, as to the guilt of the defendant. . . . Such expressions of personal opinion are a form of unsworn and unchecked testimony, and are particularly difficult for the jury to ignore because of the prosecutor’s special position. . . . Moreover, because the jury is aware that the prosecutor has prepared and presented the case and consequently, may have access to matters not in evidence ... it is likely to infer that such matters precipitated the personal opinions.” (Citations omitted; internal quotation marks omitted.) State v. Whipper, supra, 258 Conn. 263; see also A.B.A., Standards for Criminal Justice, Prosecution Function and Defense Function (3d Ed. 1993) standard 3-5.8 (b), p. 106.
The state’s attorney did on several occasions assert his personal view of the evidence.18 Some of these com[714]*714ments focused on the discrepancy that had been highlighted in defense counsel’s closing argument between the description Gansen had given to the investigator at the fire scene and the defendant’s actual physical appearance.19 The state’s attorney remarked that he considered the defendant’s physical build to be consis[715]*715tent with Gansen’s description and that neither he nor most people of Gansen’s age could guess a person’s age with accuracy.20 By doing so, the state’s attorney impermissibly vouched for Gansen’s credibility. See State v. Alexander, supra, 254 Conn. 305 (prosecutor improperly implied that “victim testified truthfully because she is young and therefore honest”).
The state contends that, because the state’s attorney prefaced his argument by explaining that his use of the first person when drawing factual inferences and reasonable conclusions was a rhetorical device that was not intended to divert the jury from making its own conclusions and inferences, the comments were not improper.21 We disagree with this contention. The prefatory remarks do not transform an otherwise improper form of argument into a proper one. They may, however, have some bearing on our determination as to whether an improper argument was prejudicial.
[716]*716III
The next claimed impropriety is that, in his closing argument, the state’s attorney referred to facts not in evidence. We reject all but two of the defendant’s claimed improprieties in this category of misconduct because the remarks were either supported by evidence, were matters of common knowledge, or had been invited by defense counsel’s remarks.22
[717]*717“A prosecutor, in fulfilling his duties, must confine himself to the evidence in the record. ... [A] lawyer shall not . . . [a]ssert his personal knowledge of the facts in issue, except when testifying as a witness. . . . Statements as to facts that have not been proven amount to unsworn testimony, which is not the subject of proper closing argument.” (Internal quotation marks omitted.) State v. Whipper, supra, 258 Conn. 275; see also A.B.A., supra, standard 3-5.9, p. 109. “[T]he state may [however] properly respond to inferences raised by the defendant’s closing argument.” State v. Robinson, supra, 227 Conn. 746.
As we previously noted, the defense had contended that the police canine, Louise, had alerted to the defendant’s shoes because the shoes had been exposed to gasoline when the defendant wore them earlier that day to the filling station. To controvert this theory, the state’s attorney commented: “Well, all by itself, it doesn’t prove anything, but it’s an amazing coincidence this dog didn’t alert to anybody else’s shoes. I think we can safely assume that Dellamura and Pettola pump gas, they are in gas stations, but even if we couldn’t, the fact is that this is the guy whose shoes had gasoline on them and it is a gasoline fire.” There was no evidence that Dellamura and Pettola ever pumped their own gas, nor more importantly, that they recently had pumped gas while wearing the same shoes that they had worn [718]*718to the defendant’s home at the time of the search. Therefore, these comments were improper.
Defense counsel also had pointed out in his closing argument that clothing that had been seized from the defendant’s apartment—a pair of black pants and a white shirt23—had not tested positive for the presence of gasoline. The state’s attorney responded to these remarks by speculating that the reason for that fact could be that the defendant had destroyed the clothes.24 This speculation was improper because it suggests a course of conduct by the defendant indicating consciousness of guilt, for which there was no evidence.
A prosecutor may invite the jury to draw reasonable inferences from the evidence; however, he or she may not invite sheer speculation unconnected to evidence. See State v. Copas, 252 Conn. 318, 336-39, 746 A.2d 761 (2000) (jury’s inferences from evidence must be reasonable and founded upon evidence and cannot be based on mere conjecture); State v. Pouncey, 241 Conn. 802, 811, 699 A.2d 901 (1997) (counsel may not suggest inference from facts not in evidence). Moreover, when a prosecutor suggests a fact not in evidence, there is a risk that the jury may conclude that he or she has independent knowledge of facts that could not be presented to the jury. United States v. Modica, supra, 663 F.2d 1178-79; see also United States v. Salameh, 152 [719]*719F.3d 88, 133 (2d Cir. 1998), cert. denied, 526 U.S. 1028, 119 S. Ct. 1273, 143 L. Ed. 2d 368 (1999) (noting that “prosecutor has a special duty not to mislead”). Because the state’s attorney in the present case asked the juiy to engage in speculation, his comments were improper.
IV
The final category of alleged misconduct is the state’s attorney’s appeal to the passions, emotions and prejudices of the jury. Specifically, the defendant claims that the state’s attorney improperly appealed to the jury’s sense of duty to the firefighters and improperly attempted to arouse hostility toward the defendant.
A prosecutor may not appeal to the emotions, passions and prejudices of the jurors. State v. Alexander, supra, 254 Conn. 307; A.B.A., supra, standard 3-5.8 (c), p. 106. “When the prosecutor appeals to emotions, he invites the jury to decide the case, not according to a rational appraisal of the evidence, but on the basis of powerful and irrelevant factors which are likely to skew that appraisal.” (Internal quotation marks omitted.) State v. Brown, supra, 256 Conn. 307. Therefore, “a prosecutor may argue the state’s case forcefully, [but] such argument must be fair and based upon the facts in evidence and the reasonable inferences to be drawn therefrom.” State v. Bova, 240 Conn. 210, 243, 690 A.2d 1370 (1997).
In the present case, the state’s attorney’s comments addressed the danger faced by the firefighters at the fire scene.25 These comments are similar to ones that [720]*720we have previously determined are proper. See State v. Brown, supra, 256 Conn. 308-309. We have permitted this type of comment when it has referred to facts in evidence about the danger testified to by the firefighters and was “highlighted ... as proof of the necessary element of the other first degree arson charge the defendant faced, namely, that the fire subjected the firefighters to a substantial risk of bodily injury.” Id.; cf. State v. Williams, supra, 41 Conn. App. 187-88 (remarks regarding danger to police improper because no evidence to support fact and irrelevant to matter before jury). The comments in the present case were supported by the firefighters’ testimony about the fire conditions and the dangers that they posed. Moreover, we note that one of the comments about which the defendant complains was made by his own counsel.
With respect to the second claim of impropriety, the defendant contends that the state’s attorney’s comments were “designed to arouse hostility, if not toward Indians, then at least to restaurant owners who owed money.” It was the defendant, however, who introduced the issue of ethnicity in an attempt to counter any prejudice that the jury might feel toward an Asian-Indian. Defense counsel argued that “[the defendant] as he sits here is a citizen of this country, he is our brother, our father and our son, and the standard of reasonable doubt that has to be put upon you is if [he] were your brother, your father, your son . . . .” The state’s attorney responded that the defendant was not the jurors’ father, brother or son, because, unlike the jurors’ relatives, the defendant was a person in debt who had been seen by an uninterested witness leaving the vicinity of [721]*721the fire scene.26 On the present facts, we conclude that it was not improper for the state’s attorney to use the same rhetorical device employed by defense counsel to underscore its theory of the case that the defendant was motivated to commit arson to get out of debt.
We do agree, however, that some of the state’s attorney’s comments improperly appealed to the emotions of the jury. Specifically, the state’s attorney conveyed his personal view of the defendant and expressed his expectations as to the conclusions the jury should reach from the evidence.27 He underscored the jury’s duty to [722]*722the prosecution by stating at the end of his closing that, if the jury could not draw the necessary inferences from the evidence presented, “then you’re not the jurors I thought I selected when I started all of this.”
The prosecutor’s office carries a special prestige in the eyes of the jury. See United States v. Young, 470 U.S. 1, 18-19, 105 S. Ct. 1038, 84 L. Ed. 2d 1 (1985) (“prosecutor’s opinion carries with it the imprimatur of the Government and may induce the jury to trust the Government’s judgment rather than its own view of the evidence”); State v. Alexander, supra, 254 Conn. 302 (recognizing that “[b]y reason of his office, [the prosecutor] usually exercises great influence upon jurors”). Consequently, “[i]t is obligatory for prosecutors to find careful ways of inviting jurors to consider drawing argued inferences and conclusions and yet to avoid giving the impression that they are conveying their personal views to the jurors.” (Internal quotation marks omitted.) United States v. Eltayib, 88 F.3d 157, 173 (2d Cir.), cert. denied, 519 U.S. 1045, 117 S. Ct. 619, 136 L. Ed. 2d 543 (1996); accord United States v. Torres, 809 F.2d 429, 447 (7th Cir. 1987) (Flaum, J., concurring) (“it is improper for a prosecutor to personalize his or her arguments”). An appeal to the jury to decide the case out of a sense of duty to the state or the prosecutor diverts the jury from its true mission: to decide whether the state has proven beyond a reasonable doubt that the defendant committed a crime. See United States v. Manning, 23 F.3d 570, 573 (1st Cir. 1994) (arguments that law and justice compel conviction amount to “improper appeals to the jury to act in ways other than as a dispassionate arbiter of the facts”); United States v. [723]*723Mandelbaum, 803 F.2d 42, 44 (1st Cir. 1986) (suggestion that jury has duty to decide case one way or another “is designed to stir passion and can only distract a jury from its actual duty: impartiality”); see also State v. Pouncey, supra, 241 Conn. 811 (prosecutor should avoid argument that “ ‘would have the effect of diverting the jury’s attention from their duty to decide the case on the evidence’ ”). Because the remarks in the present case implied that the jury’s obligation was to the state’s attorney and not solely to make an unbiased determination whether the evidence indeed established the defendant’s guilt beyond a reasonable doubt, they were improper.
V
The ultimate question is, in light of the conduct that we have concluded was improper, whether the “trial as a whole was fundamentally unfair and that the misconduct so infected the trial with unfairness as to make the conviction a denial of due process.” (Internal quotation marks omitted.) State v. Alexander, supra, 254 Conn. 303. This final determination requires, as we have stated previously, the consideration of several factors: the extent to which the misconduct was invited by defense conduct or argument, the severity of the misconduct, the frequency of the misconduct, the centrality of the misconduct to the critical issues in the case, the strength of the curative measures adopted and the strength of the state’s case. See State v. Whipper, supra, 258 Conn. 262-63. We conclude that the defendant was deprived of a fair trial.
Although many of the improprieties were not serious, and referred to secondary or collateral issues, there were four notable exceptions: (1) the questions and comments about witnesses’ veracity, in particular, the statements in closing argument that, in order to believe the defendant, the jury would have to conclude that [724]*724Gansen had lied; (2) the remark that Pettola and Dellamura may have pumped gasoline while wearing the same shoes they wore at the defendant’s apartment; (3) the remarks suggesting that the defendant may have destroyed the clothing that he had worn the night of the fire; and (4) the state’s attorney’s final remarks suggesting that the jury’s duty of loyalty lay with the prosecution.
The prejudicial effect of these comments results from two factors. First, the state’s evidence, while sufficient to result in a conviction, was not particularly strong. Indeed, the state’s motive evidence was particularly weak—the defendant did not stand to gain in any material way from the fire, with the possible exception of being released from his lease due to the fire clause. More important, there were only two pieces of evidence to connect the defendant to the crime: Gansen’s identification of the defendant, which was, in several respects, inconsistent with the description of the person he had given to the police on the night of the fire; see footnote 19 of this opinion; and the defendant’s shoes containing traces of a type of gasoline that could not be traced directly to the fire. See footnote 9 of this opinion.
The second, and related, factor indicating the prejudicial effect of the state’s attorney’s misconduct was that all of the improprieties were connected directly to the critical issue, indeed the only disputed issue at trial— namely, the identity of the arsonist. See State v. Alexander, supra, 254 Conn. 308 (concluding that prejudice resulted when improper comments addressed critical issue of credibility of victim and state’s case was not particularly strong). It is noteworthy that the improper comments regarding this evidence were made both during cross-examination and in closing arguments. Compare United States v. Weiss, supra, 930 F.2d 195 (finding conduct nonprejudicial when subject of improper cross-examination not highlighted by calling rebuttal witness [725]*725or emphasizing in closing argument) with State v. Alexander, supra, 308 (finding misconduct “pervasive” when comments made both in initial summation and on subsequent rebuttal argument). In the absence of any independent evidence to corroborate the identity of the defendant as the arsonist, we cannot conclude that, had the jury not been exposed to these improper remarks, it would have concluded that the evidence proved beyond a reasonable doubt that the defendant had committed the arson. Accordingly, the defendant was deprived of a fair trial.
The judgment of the Appellate Court is reversed and the case is remanded to that court with direction to reverse the judgment of the trial court and to remand the case for a new trial.
In this opinion SULLIVAN, C. J., and NORCOTT and ZARELLA, Js., concurred.