concurring in the judgment.
1 24 The majority approves the admission of opinion testimony from investigating detectives that they "didn't believe" one witness, felt another "obviously hadn't been entirely truthful," and that another's information was "true." To do so, the majority fashions an exception to CRE 608 for opinion testimony offered for the limited purpose of providing "context for the detective's interrogation tactics and investigative decisions." Maj. op. 19. In my view, the majority's exception conflicts with precedent categorically prohibiting such testimony and the clear dictates of CRE 608.
1 25 I would hold that the trial court erred by permitting admission of the opinion testimony commenting on the witnesses' veracity in this case. Finding error, I would nevertheless conclude that admission of the testimony was harmless and would affirm the defendant's convictions. Although the majority finds it unnecessary to reach this issue, because I find error, I address whether an opening statement can open the door to otherwise inadmissible evidence. And I would hold that opening statements cannot open the door to otherwise inadmissible evidence, and I would vacate that portion of the court of appeals' opinion holding otherwise.
( 26 Hence, I concur in the judgment.
I.
127 A witness may not be asked to opine on the veracity of another witness. Liggett v. People, 135 P.3d 725, 732 (Colo.2006). Testimony about another witness's veracity invades the province of the jury, lacks probative value, distorts the government's burden of proof, creates a "no win" situation, and is argumentative. Id. at 731-32. Liggett's rule prohibiting admission of such testimony is categorical, affording no room for any case-by-case exception. Id. at 732.
128 The majority fashions such an exception, distinguishing Liggett because the prosecution did not ask "were they lying?" but instead asked questions concerning the detectives' investigative decisions. The majority reads Liggett too narrowly. The concerns underlying Liggett do not disappear because testimony is offered for the limited purpose of explaining the context of a detective's "interrogation tactics and investigative decisions." Nor am I persuaded that the prosecution's questions, rather than a witness's responses, are the focal point of the inquiry. Liggett offers no principled basis on which to distinguish "were they lying" questions from "they were lying" statements-both are "categorically improper." See id. at 7322. In *65either case, the jury learns a witness's opinion about the veracity of another witness on a particular occasion, and "clothing the opinion in the garb of an interviewing technique does not help." State v. Elnicki, 279 Kan. 47, 105 P.3d 1222, 1229 (2005) (quoting State v. Jones, 117 Wash.App. 89, 68 P.3d 1153, 1155 (2003)).
129 More fundamentally, the majority's holding, though framed as an exception to CRE 608, rewrites that rule. CRE 608 controls the admissibility of character evidence offered to support or attack the credibility of a witness. By its terms, CRE 608 does not permit admission of a witness's opinion about whether another witness was telling the truth on a particular oceasion-such as the interrogations at issue here. CRE 608(a); Liggett, 135 P.3d at 731. Until today, our cases have uniformly held as much. See, e.g., People v. Eppens, 979 P.2d 14, 18 (Colo.1999) (holding that a social worker's testimony that a child was "sincere" constituted impermissible character testimony); People v. Gaffney, 769 P.2d 1081, 1088 (Colo.1989) (holding that CRE 608(a) prohibited admission of a pediatrician's statement that a child's medical history was "very believable"). Further, CRE 608 does not permit testimony bolstering a witness's character for truthfulness before that character has been attacked, nor does it permit testimony about specific instances of conduct on direct examination. But the majority's holding appears to permit both so long as the testimony provides context for the interrogation tactics and investigative decisions of law enforcement officials Additionally, such testimony appears admissible without any of the rule's foundational safeguards-such as the requirement that the testifying witness actually know the witness to be impeached or bolstered. Honey v. People, 713 P.2d 1300, 1302 (Colo.1986).
130 Finally, the exception fashioned by the majority is unnecessary. Assuming such testimony is relevant, there are other ways for a law enforcement official to provide "context for the detective's interrogation tactics and investigative decisions" without permitting admission of opinion testimony about a witness's veracity on a particular occasion. The prosecution could ask general questions about how the interrogation or investigation progressed, or, even more generally, questions about how police routinely conduct interrogations and investigations. See Elnicki, 105 P.3d at 1229. Here, the prosecution asked the detective why an interrogation became confrontational, and she testified that "being more confrontational" is an interrogation tactic designed to encourage witnesses to divulge information and that she regularly "accuse[s] the interviewee" of being involved in a crime to garner information, which escalated an interrogation here. Neither reason required the detective to opine on a witness's veracity, yet both provide context for her interrogation tactics and investigative decisions.
1 31 Finding error, I would address whether permitting admission of the detectives' testimony was harmless. Having reviewed the record, and consistent with our precedent, I am persuaded that it was. As the majority makes clear, although the detectives opined about the veracity of three witnesses, all three testified at trial and were subject to vigorous eross-examination. The jury was free to assess their credibility on its own. See Eppens, 979 P.2d at 18 (holding that a social worker's comment that a child appeared "sincere," though error, was harmless in part because the child was subject to cross-examination and the jury had a "full opportunity to judge her eredibility in light of her demeanor"). Although the trial court should have stricken the improper testimony, it did provide a limiting instruction in one instance, and it also instructed the jury on several occasions, in accordance with Colorado's model jury instructions, of the jury's responsibility to assess the credibility of witnesses on its own.
IL
132 Finding the testimony inadmissible, I address whether opening statements can open the door to otherwise inadmissible evidence. In my view, the answer is clear-they cannot. Hence, I would vacate that portion of the court of appeals' opinion holding otherwise.
1 33 Opening statements are not evidence, and they do not constrain later argument or *66introduction of evidence. See People v. Bergerud, 223 P.3d 686, 700 (Colo.2010). The trial court's introductory instructions to the jury are explicit "Opening statements are not evidence. Their purpose is only to help you understand what the evidence will be." CJI-Crim. 1:03 (1983). If, in an opening statement, counsel makes an improper remark, then the remedy lies in a curative instruction or, in some cases, a mistrial,. See State v. Amastasia, 356 N.J.Super. 534, 813 A2d 601, 606 (App.Div.20083). If counsel promises to present certain evidence during opening statements and does not, then opposing counsel may attack that failure during closing. See State v. Chum, 54 A.Sd 455, 461 (R.12012). What is inappropriate, however, is permitting opposing counsel to present irrelevant or otherwise inadmissible evidence on the basis that an opening statement, which carries no evidentiary weight, opened the door to its admission.1
1 34 Hence, I concur in the judgment.
I am authorized to state that Justice MARQUEZ joins in the concurrence in the judgment.
. As the People and the court of appeals point out, however, there are cases from other jurisdictions holding otherwise. See, eg., Flanders v. State, 279 Ga. 35, 609 S.E.2d 346, 351 (2005) (concluding that defense counsel's remark during opening statements opened the door to testimony but concluding alternatively that the testimony was cumulative of other testimony admitted without objection). Contrary to such cases, my view is that the remedy to an improper opening statement lies in a curative instruction or a mistrial.