The defendant was convicted by a jury of rape of a child, his ten year old nephew, whom we shall call Steven. The Appeals Court reversed the defendant’s conviction, set aside the verdict, and remanded the case for a new trial because in a pretrial order a motion judge had improperly ruled Steven’s mental health records inadmissible at trial. In reaching its conclusion, the Appeals Court reviewed the records in question and concluded that the records contained information that could have supported the defendant’s contention that his nephew had imagined the incident. Thus, that court concluded that the records were sufficiently probative that their exclusion deprived the defendant of a fair trial. Commonwealth v. Sheehan, 48 Mass. App. Ct. 916 (2000). We granted the Commonwealth’s application for further appellate review. We have also examined the records in question. We agree with the result of the Appeals Court and for substantially the reasons set forth in its opinion.
The relevant facts may be summarized as follows. On August 17, 1993, the defendant invited Steven to spend the night at his house and Steven’s mother agreed. Steven seemed immature for his age and was known to have a slight learning disability. He and his mother had previously lived with the defendant, and Steven had a good relationship with the defendant.
The defendant and Steven arrived at the defendant’s house at approximately 12:30 a.m. The defendant fixed Steven a snack, and Steven prepared for bed. Steven claims that the defendant came into the bedroom with butter. Steven was lying on his stomach and remembers that his clothes “got off” but did not know how or when they were removed. According to Steven, the defendant put butter on Steven’s “butt” and inserted his penis in Steven’s rectum for “a couple of seconds.” Steven asserts that the defendant then put his penis in Steven’s mouth and told Steven that he would “give [him] a dollar” if he let the defendant keep his penis in Steven’s mouth for the rest of the night. Steven claimed that he does not remember how long the defendant’s penis was in his mouth but that he slept in the defendant’s bed with the defendant. The defendant asserts that after he fixed Steven a snack, Steven fell asleep on his bed, and that he spent the night sleeping on the living room sofa.
The next morning the defendant returned Steven to his home. *185Steven told his mother that the defendant had “put his pee-pee in my bum-bum.” His mother claims that she asked the defendant what happened and that the defendant responded that nothing had happened and left.
Steven’s mother then took him to a hospital. Dr. Deborah Hartley visually examined Steven’s rectum and found no bleeding or tearing of the rectal tissue. The doctor did not perform a digital examination or administer a rape kit.
The next day, Steven and his mother spoke with Detective Ralph N. Fomi of the Wareham police department. Steven told the detective that the defendant had “put butter on my bum and licked my pee-pee.” Detective Fomi informed the defendant of Steven’s allegations the following day. The defendant stated that he believed he should contact an attorney, and Detective Fomi allowed the defendant to return home.
Prior to trial, in accordance with the procedure set forth in Commonwealth v. Bishop, 416 Mass. 169, 179-183 (1993) (Bishop procedure),1 the defendant filed a motion seeking access to Steven’s mental health records.2 On November 21, 1995, a judge in the Superior Court (motion judge) ruled that the *186defendant had demonstrated a theory on which the records were likely to be relevant and ordered that all records of South Bay Mental Health Center and the Department of Social Services (DSS)3 be made available to both counsel subject to a protective order.4 After this point, the course of the proceedings becomes less clear. On November 6, 1996, the same motion judge caused a handwritten notation to be made on the face of the November 21, 1995, order: “[ajfter [rjeview of [ijmpounded [rjecords, the [cjourt finds no exculpatory [ejvidence for [ujse at [tjrial.”5 It is this 1996 order that forms the subject of this appeal. The defendant argues that the records of South Bay Mental Health Center and DSS revealed that Steven had difficulty distinguishing fantasy from reality and that he fantasized to escape anxiety-provoking situations; because the defense was that Steven fantasized the event in question, the records were relevant to that defense, and the judge’s nondisclosure order deprived the defendant of the use of the records to assist his defense.
The first problem presented by this case is procedural. By her order of November 21, 1995, the motion judge indicated that she had determined the records to be relevant pursuant to a Bishop Stage Two determination.6 Her protective order of the same date was in compliance with Stage Three of; the Bishop procedure.7 Thus, at this point any further proceedings regarding the records presumably would be governed by Stage Four *187of the Bishop procedure. Stage Four requires that the defendant demonstrate that disclosure of the relevant portions of the records to the trier of fact is required to provide the defendant a fair trial. If so, the judge is to permit disclosure of those portions of the records shown to be needed to prepare and mount a defense.
In arriving at this determination, the judge is to base his or her decision on written motions by the parties and an in camera hearing as the judge deems necessary. “In any case, the judge shall set forth in writing the reasons for the decision in a memorandum of decision.” Commonwealth v. Bishop, supra at 183.* ******8 But the parties were not required to provide the Stage Four written motions; the judge did not set forth in writing the reasons for her decision; and, as far as the record reveals, no hearing (in court or in camera) was held. All that is before us is the judge’s notation that the records are not exculpatory for use at trial. We take this to be a determination by the judge that the defendant had not met his Stage Four burden of demonstrating that disclosure of the records to the trier of fact was necessary to provide the defendant a fair trial. We do so because of the *188prior rulings on the issue by the motion judge (apparently made pursuant to Stages Two and Three of the Bishop procedure) and because the parties have not indicated that any other stage applies.9
Regardless of the posture in which this issue was presented, the motion judge should have conducted a Stage Four proceeding to determine whether the defendant could demonstrate that disclosure of the relevant portions of the records was necessary for the purpose of preparing and mounting a defense. We keep in mind that in making the Stage Four decision, the judge is to “resolve any doubt ... in the defendant’s favor.”10 Commonwealth v. Bishop, supra at 183. As in many cases of this nature, the trial was a credibility contest between the complainant and the defendant. There was no corroboration from physical evidence or eyewitness testimony. The defense was that the ten year old complainant, who had a learning disability, was immature for his age, had difficulty distinguishing fantasy from reality and had imagined the incident.11
An examination of the records that the defendant was prohibited from disclosing to the trier of fact reveals that they contain statements that the complainant did have some tendency to fantasize inappropriately and to converse in his mind with his deceased grandmother. The records also state: “His cognitive processing of information presented to him seems somewhat unsophisticated and immature, which may predispose him to less effective interpretations of events in his environment.” This information provides abundant fodder for cross-examination of Steven and his mother as to the reality of the child’s perceptions.
We recognize that the defendant was not deprived completely *189of his defense. He was able to cross-examine Steven at trial regarding the fact that, when he was ten years old (his age at the time of the alleged incident) he still believed in Santa Claus and the Tooth Fairy and that he would pretend he was a “Power Ranger.” Steven said that he thought he believed at age ten that the “Power Rangers” were real. This evidence, however, is not nearly as compelling as evidence of mental health professionals regarding the boy’s perception difficulties. The records provided evidence that “went directly to the issue of [the complainant’s] credibility, the core issue to be resolved by the jury.” Commonwealth v. Pare, 427 Mass. 427, 431 (1998). The evidence “could have made it more likely, in the jury’s view, that the complainant did not perceive the event accurately . . . [and] could have been helpful for the jury to determine whether the complainant was telling the truth or whether [he] imagined the entire incident.” Commonwealth v. Fayerweather, 406 Mass. 78, 83 (1989).12
The Commonwealth argues that the admission of the complainant’s mental health records would not have benefited the defendant because the complainant had no psychiatric history prior to the alleged rape and the therapists all describe Steven’s fantasizing as a coping mechanism. It is true that the treatment did not begin until after the alleged rape and that it was precipitated by marked changes in the child’s behavior (sleep disturbances, more anger and aggressiveness, fear, and bed-wetting). Although the reports do indicate that these problems were due to the alleged rape and did not occur before it, the records at least provide a basis for the premise that the child’s fantasies predate the alleged rape and were the result of his grandmother’s death and the absence of a father in his life. The records provide a basis for cross-examination about the possibility that these earlier events in Steven’s life caused him to fantasize and have problems separating reality from fiction. The records also state that the boy’s mother believed that his *190immaturity was the result of a serious illness (mononucleosis) when he was seven years old. They further state that Steven has a hearing problem that interferes with his understanding in class and that the hearing problem needed follow-up examination. All these issues could have been examined at trial in an effort to impair Steven’s credibility. See Commonwealth v. Fayerweather, supra.
To the extent that the records were damaging to the defense (by suggesting that the alleged rape did in fact occur), it was for defense counsel to decide whether their value outweighed their harm. Counsel was deprived of the ability to make that choice by the judge’s ruling. Commonwealth v. Bishop, supra at 182-183.
The Commonwealth argues that the defendant was obliged to raise the issue of the admissibility of the records at trial and that the defendant made a reasonable tactical choice not to seek to introduce the records because of their tendency to suggest that Steven’s mental health problems were due to the rape..We agree with the Appeals Court, however, that it appears from the transcript that the parties considered themselves bound by the motion judge’s order of exclusion.
Even if an objection at trial were required, the error in the ruling on the records created a substantial risk of a miscarriage of justice. See Commonwealth v. Comtois, 399 Mass. 668, 674 (1987), citing Commonwealth v. Freeman, 352 Mass. 556, 564 (1967). The records were needed to support the defense; without them, it was simply the defendant’s word against Steven’s. The Commonwealth’s case rested almost entirely on the testimony of the complainant. “[T]he . . . evidence, if believed, might have had a significant impact. . . on the outcome of the trial.” Commonwealth v. Bohannon, 376 Mass. 90, 95 (1978), S.C., 385 Mass. 733 (1982). “When evidence concerning a critical issue is excluded and when that evidence might have had a significant impact on the result of the trial, the right to present a full defense has been denied.” Id. at 94, and cases cited.
Although our ruling on the Bishop issue requires reversal, we comment on the defendant’s claim that the prosecutor, in his closing argument, improperly attacked the defendant by labeling him a “predator” who “picked the weak chick to prey upon.” *191The defendant made timely objection to this remark at the close of the Commonwealth’s argument. See Commonwealth v. Person, 400 Mass. 136, 139 (1987). “Predator” is defined as “one that preys, destroys, or devours.” Webster’s Third New Int’l Dictionary at 1785 (1993). Although “[hjyperbole in closing arguments is hardly rare, and juries should be given credit for the ability to filter out oratorical flourishes,” Commonwealth v. Griffith, 45 Mass. App. Ct. 784, 787 (1998), there is no support in the evidence for labelling the defendant a “predator,” and the remark was unwarranted.
The judgment of conviction is reversed, the verdict is set aside, and the case is remanded to the Superior Court for a new trial.
So ordered.
At the time of the filing of the motion in this case, the Bishop procedure, Commonwealth v. Bishop, 416 Mass. 169 (1993), mandated a five-stage procedure for defendants seeking access to treatment records of complainants in sexual assault cases. Stage One was a determination whether the records were privileged. If they were, Stage Two required that the defense submit to the judge in writing “the theory or theories under which the particular records sought [were] likely to be relevant to an issue in the case.” Id. at 181-182. If the judge decided that the defendant’s proffer established that the records were likely to be relevant, the judge reviewed the records in camera to determine whether any of the materials were relevant. These portions were then made available to the defense attorney and the prosecutor subject to a protective order (Stage Three). Id. at 182. The Stage Two procedure established in Commonwealth v. Bishop, supra, was later modified in Commonwealth v. Fuller, 423 Mass. 216, 226 (1996), to provide that the judge is to consider whether the defendant by motion “has demonstrated a good faith, specific, and reasonable basis for believing that the records will contain exculpatory evidence which is relevant and material to the issue of the defendant’s guilt,” and whether the material is available elsewhere. The appropriate standard for the Stage Two determination is not at issue.
The records originally sought were those of counsellors from South Bay Mental Health Center, the Department of Social Services, and a Dr. Triberg of Pembroke Hospital. The record does not reveal any further proceedings regarding the records of Dr. Triberg and the parties have not raised any issue concerning those records.
The order referred to records of South Bay Mental Health Center, the Department of Social Services, and Dr. Deborah Hartley. Dr. Hartley examined Steven the morning after the alleged incident. Her records are not relevant to the issues herein.
In compliance with Stage Three of Commonwealth v. Bishop, supra at 182, 189, the order provided that counsel for both parties were to have access to the subject records (and could make notes therefrom), but that the contents thereof were not to be photocopied or reproduced in any way or disclosed to anyone, including the defendant, without prior “application to and an order of the court.” The order also provided that counsel could not offer any portion of the records at trial except on order of the court.
Apparently the judge reviewed the records sometime after she issued the Stage Three order. According to the Bishop procedure, the records are to be reviewed by the judge as part of Stage Two, prior to their being made available to counsel. See note 1, supra.
See note 1, supra.
Stage Three provides as follows: “The judge shall allow defense counsel and the prosecutor access to the relevant portions of the privileged records for *187the sole purpose of determining whether disclosure of the relevant communications to the trier of fact is required to provide the defendant a fair trial.
“The judge shall ensure that breaches of confidentiality attending access to the relevant portions of the privileged records are limited only to those absolutely and unavoidably necessary. Any records so examined shall be subject to a protective order of the type presented in the Appendix to this opinion to ensure that the information will not be divulged beyond the extent required for the purpose stated above. The judge shall allow counsel access to the privileged records only in their capacity as officers of the court.” Commonwealth v. Bishop, 416 Mass. 169, 182 (1993).
Stage Four provides as follows: “The burden is on the defendant to demonstrate that disclosure of the relevant portions of the records to the trier of fact is required to provide the defendant a fair trial. If the defendant meets this burden, the judge shall permit the disclosure of those portions of the records which are shown to be needed for the purpose of preparing and mounting a defense. The judge may condition disclosure on appropriate terms and conditions. In arriving at this determination the judge shall resolve any doubt he or she may have in the defendant’s favor. The judge shall base his or her decision on written motions by the parties and an in camera hearing as the judge deems necessary. In any case, the judge shall set forth in writing the reasons for the decision in a memorandum of decision. The judge should identify any undisclosed materials so that in the case of conviction and appeal they may be sealed and transmitted to the reviewing court.” Commonwealth v. Bishop, supra at 182-183.
Defense counsel suggested at oral argument that the judge’s handwritten 1996 order may have been prompted by a motion in limine filed by the Commonwealth to exclude the records from trial. The record does not reflect such a motion, although the transcript indicates that the assistant district attorney stated at a bench conference that the Commonwealth filed the motion that prompted the order.
We are aware that the judge in this case did not have the benefit of written motions by the parties. See Commonwealth v. Bishop, supra at 182-183, regarding Stage Four.
This had consistently been the theme of the defense, as indicated by an affidavit of relevancy filed by the defendant approximately one year prior to trial in connection with another Bishop motion.
The harm to the defendant from the absence of the material in the records was accentuated by the difficulties of preparing a defense on the facts in this case: Steven had previously been on very good terms with his uncle (and thus had no apparent motive to fabricate); and there was a four-year delay between the alleged rape and the date of trial, during which time Steven had become more mature.