State of Minnesota, Appellant, vs. Angel Dominguez Perez, a/k/a Edgar Luis Ceballos, Respondent.

 STATE OF MINNESOTA
 IN COURT OF APPEALS
 C9-99-883

State of Minnesota,
Respondent,

vs.

Elmer Ringler, Jr.,
Appellant.

 Filed December 28, 1999
Reversed and remanded
Lansing, Judge

Aitkin County District Court
File No. K0-96-260

Mike Hatch, Attorney General, 525 Park Street, Suite 500, St. Paul, MN 55103; and

Bradley C. Rhodes, Aitkin County Attorney, Courthouse West Annex, Aitkin, MN 56431 (for respondent)

Douglas G. Sauter, Jason P. Rietz, 199 Coon Rapids Boulevard, Suite 108, Coon Rapids, MN 55433 (for appellant)

Considered and decided by Lansing, Presiding Judge, Shumaker, Judge, and Foley, Judge.[*]

 U N P U B L I S H E D   O P I N I O N

 LANSING, Judge

This appeal from the denial of postconviction relief for conviction of criminal sexual conduct raises the issue of ineffective assistance of trial counsel. The postconviction court found that trial counsel made numerous errors and was generally unprepared, but concluded that the errors did not require a new trial. The evidence amply sustains the district court's findings on trial counsel's errors and lack of preparation. These findings, the trial transcript, and the postconviction hearing transcript compel a conclusion that trial counsel's representation was professionally unreasonable. Because the gravity of the errors undermines confidence in the fairness and reliability of the proceedings, we reverse and remand for a new trial.

 FACTS

A jury convicted Elmer "Jack" Ringler, Jr., of one count of first-degree criminal sexual conduct, Minn. Stat. § 609.342 (1996), and two counts of third-degree criminal sexual conduct, Minn. Stat. § 609.344 (1996). Ringler appealed, and we affirmed his conviction in an unpublished opinion. State v. Ringler, No. C2-97-1644, 1998 WL 313584 (Minn. App. June 16, 1998). We declined, however, to decide the issue of ineffective assistance of counsel because the record contained too little information to assess the merits of the claim. Id. at *1. The unpublished opinion specifically provided that Ringler was not foreclosed from initiating postconviction proceedings to establish his ineffective-assistance-of-counsel claim. Id.

Following the direct appeal, Ringler filed a petition for postconviction relief. Ringler's petition alleged that his trial attorney was ineffective in failing to request reporting of voir dire, failing to exercise peremptory challenges against two jurors, failing to sequester witnesses, failing to object to 11 questions eliciting inadmissible testimony, failing to move for a mistrial, failing to interview or prepare witnesses, and failing to object to an improper jury instruction. Ringler further alleged that his trial attorney's poor health prevented him from reasonably and competently representing him at trial.

A district court judge, who was not the trial judge, conducted a hearing on the postconviction relief petition. Seven witnesses testified, including an expert witness, a former president of the Anoka County Bar Association and the Minnesota Association of Criminal Defense Lawyers. The expert witness testified that Ringler's trial representation generally fell below an objective standard of reasonableness, but was particularly unreasonable in failing to strike two jurors and in calling a witness whose testimony was adverse to Ringler's defense. The expert witness testified that, in his opinion, the errors were of sufficient magnitude to affect the outcome of the trial. Ringler's trial attorney did not testify.

The state did not respond to the postconviction petition either by motion or answer, but an attorney representing the state appeared and fully participated in the postconviction proceeding. The postconviction court made detailed findings that identified a number of trial-counsel errors. It also found that the trial counsel displayed a general lack of preparation. Acknowledging the limitations imposed by not having been the trial judge, the postconviction court concluded that the errors did not require a new trial. This appeal followed. The state declined to submit a brief.

D E C I S I O N

A petitioner seeking postconviction relief has the burden of establishing, by a fair preponderance of the evidence, facts that warrant reopening the case. Minn. Stat. § 590.04, subd. 3 (1998). On appeal, Minnesota courts apply an abuse-of-discretion standard to the postconviction court's decision on whether to grant relief. State v. Doppler, 590 N.W.2d 627, 632-33 (Minn. 1999). The abuse-of-discretion standard was first applied to newly discovered evidence, but is now generally applied to both evidentiary and constitutional claims. Compare Scruggs v. State, 484 N.W.2d 21, 25 (Minn. 1992) (applying abuse-of-discretion standard to alleged constitutional error), with Bolander v. State, 978 F.2d 1079, 1083 (8th Cir. 1992) (classifying both performance and prejudice components of ineffectiveness inquiry as mixed question of law and fact and applying, respectively, independent review and clearly erroneous standard).

Ringler's postconviction-relief petition is grounded on his claim that his trial attorney's ineffective assistance deprived him of his Sixth Amendment right to counsel. Minnesota has adopted the two-part test of Strickland v. Washington, 466 U.S. 668, 104 S. Ct. 2052 (1984), for determining whether to grant a new trial based on ineffective assistance of counsel. Scruggs, 484 N.W.2d at 25. The defendant must first prove that counsel's representation fell below "an objective standard of reasonableness." Id. (quoting Strickland, 466 U.S. at 688, 104 S. Ct. at 2064). The defendant must also "prove that there is a reasonable probability that, but for counsel's unprofessional errors, the result of the proceeding would have been different." Id. (quoting Strickland, 466 U.S. at 694, 104 S. Ct. at 2068). "A reasonable probability is a probability sufficient to undermine confidence in the outcome." Strickland, 466 U.S. 694, 104 S. Ct. at 2068.

Ringler argues that his trial counsel's conduct was prejudicially ineffective in three ways: (1) failure to strike biased jurors; (2) failure to prepare for trial by reading the police reports and preparing the witnesses; and (3) failure to safeguard procedural rights by sequestering witnesses, objecting to inadmissible evidence, and seeking a mistrial. We address first whether the trial attorney's representation was professionally unreasonable and then turn to whether any professionally unreasonable representation requires a new trial.

 I

Ringler first asserts that his trial counsel ineffectively represented him when he failed to strike two jurors: one who had previously been sexually abused and one who had been hired by and was a good friend of the complaining witness's mother.

Neither the attorney nor the state requested that voir dire be recorded, but at the postconviction hearing Ringler and other witnesses who were present during voir dire testified to their recollections. Their testimony indicates that the trial court conducted supplemental inquiry of the two jurors in chambers. The prosecutor questioned both jurors and asked them if they could remain fair and impartial. The jurors responded that they could. Ringler's attorney did not independently question the jurors and automatically accepted them after the prosecutor's inquiry. During the in-chambers questioning, Ringler sat across from his attorney. Because he is unable to read or write, Ringler could only communicate orally. When Ringler raised his hand and tried to tell his attorney that he did not want the juror who had been sexually abused to sit on the jury, his attorney approached him and told him to "shut up." The expert witness at the postconviction hearing testified that the representation during voir dire was professionally unreasonable.

Defense counsel's performance is presumed to be reasonably effective. State v. Powell, 578 N.W.2d 727, 731-32 (Minn. 1998). A trial attorney's performance is deemed effective if counsel exercises "the customary skills and diligence that a reasonably competent attorney would exercise under the circumstances." Doppler, 590 N.W.2d at 633 (citation omitted). Juror bias may arise when a juror has been a victim of the same type of crime with which the defendant is charged. See United States v. Calabrese, 942 F.2d 218, 226 (3rd Cir. 1991) (noting implied bias justified excusal for cause when juror was victim of same type of crime being tried); see also United States v. Devery, 935 F. Supp. 393, 404 (S.D.N.Y. 1996) (stating courts may imply bias when a "prospective juror has been the victim of a crime or experienced a situation similar to the one at issue in the trial") (citation omitted). Defense counsel's failure at least to question the juror who had been a victim of sexual abuse suggests that the attorney did not exhibit the skills a reasonably competent criminal defense attorney would have exhibited under similar circumstances. See generally Johnson v. Armontrout, 961 F.2d 748, 755 (8th Cir. 1992) (holding trial counsel was ineffective for failing to request removal of jurors who did not respond to question about bias and had previously sat on jury convicting another of involvement in same crime).

The limitations of the record impede an analysis of why the trial attorney did not strike the juror or request that she be excused for cause. The record shows that Ringler's attorney ultimately used five preemptory challenges. We have no indication why the attorney exercised preemptory challenges against jurors other than the juror with the sexual-abuse history. We also lack knowledge of the prosecutor's full questioning of the juror. On this limited record, we agree with the postconviction court's analysis that the attorney's failure to challenge could have been a reasonable tactical decision. See Tsipouras v. State, 567 N.W.2d 271, 275 (Minn. App. 1997) (recognizing strong presumption in favor of effectiveness when trial strategy involved), review denied (Minn. Sep. 18, 1997); see also State v. Williams, 361 N.W.2d 473, 476 (Minn. App. 1985), review denied (Minn. April 12, 1985) (holding trial court did not err in failing to excuse juror who had been victim of armed robbery when juror stated he could be fair and impartial).

  Similarly, Ringler's attorney's failure to strike the juror who had an employment relationship with the complainant's mother does not, by itself, demonstrate that the representation was unreasonable. It is unusual that the trial attorney did not inquire into this juror's relationship to the complainant. But Ringler has not established that the juror should have been stricken for cause. See Minn. R. Crim. P. 26.02, subd. 5(1)(6) (listing for-cause challenges to include employer-employee relationship between juror and person allegedly injured by offender). The juror stated that she could remain fair and impartial. See State v. Stufflebean, 329 N.W.2d 314, 318 (Minn. 1983) (holding district court did not err in refusing to dismiss two members of jury panel who were employees of corporation owned in large part by victim's family).

 II

Ringler contends that his trial attorney's most egregious errors were calling Harold Lucht as a witness, interviewing Lucht only for a couple of minutes, and failing to read the sheriff's report that contained statements Lucht made to another neighbor that he suspected a relationship between Ringler and the complainant and spoke to Ringler about it.

Harold Lucht, a bailiff in the Aitkin courthouse, was highlighted as a pivotal witness in Ringler's defense. In his opening statement, the attorney told the jury "that a number of people will testify how they saw the relationship between Jack and [the complainant] * * * ." He then specifically highlighted the upcoming testimony of Ringler's best friend, Lucht.

Ringler's trial attorney, however, failed to read the statement the neighbor made to the police, which the state had previously disclosed to him. In that statement, the neighbor reported to the sheriff's investigator that Lucht had told her that he suspected a sexual relationship between Ringler and the complainant, and Lucht had confronted Ringler about the relationship and told Ringler if the relationship was occurring he should "knock it off."

At the postconviction relief hearing, Lucht testified that he was totally unprepared to testify at trial. Ringler's trial attorney called him by telephone a few months before the trial to ask if he would be a witness for Ringler. The conversation lasted about one minute and the attorney did not go over any testimony at that time. Lucht spoke with the attorney one more time, the day of Lucht's scheduled testimony. That testimony occurred outside the courtroom door before Lucht was to testify and lasted only one or two minutes. Lucht asked the attorney what the questions were, and the attorney told Lucht, "We'll play it by ear." Lucht expressed concern about that approach. The state did not note Lucht as a witness or call Lucht to testify. The only reason Lucht's testimony was before the jury was that Ringler's attorney called Lucht.

Generally, this court will not pass judgment on counsel's trial tactics. State v. Ronquist, 578 N.W.2d 4, 7 (Minn. App. 1998), aff'd, 600 N.W.2d 444 (Minn. 1999). Which witnesses to call and what evidence to present are matters of trial strategy, within the discretion of trial counsel. Gustafson v. State, 477 N.W.2d 709, 713 (Minn. 1991). But the supreme court has also stated that insufficient preparation for trial may be grounds for finding ineffective assistance of counsel. In Re Welfare of T.D.F., 258 N.W.2d 774, 775 (Minn. 1977) (citing Grattan v. Tahash, 262 Minn. 18, 113 N.W.2d 342 (1962)); see also Gates v. State, 398 N.W.2d 558, 563-64 (Minn. 1987) (stating duty of reasonable defense attorney might include interview of witnesses named in police reports). Lucht's prior statement, fully disclosed by the county attorney, implies admission of Ringler's guilt. See State v. Wiplinger, 343 N.W.2d 858, 861 (Minn. 1984) (holding an unauthorized implied admission of guilt by a defendant's trial counsel may require a new trial). Although the attorney did not directly elicit the testimony from Lucht, the attorney called Lucht as a witness and minimum preparation would have revealed Lucht's opinion and prior statements. The insufficient preparation, coupled with the decision to call Lucht to testify, was not professionally reasonable. These actions demonstrate the lack of skill and diligence a reasonably competent defense attorney would have exhibited under similar circumstances.

Ringler also asserts deficiencies in his trial counsel's failure to prepare other defense witnesses. The postconviction record provides uncontroverted evidence that the attorney spoke with two alibi witnesses only for a couple of minutes on the day of trial and to a third witness only briefly on the phone. Ringler's wife testified that she was also inadequately prepared and was unaware that a police report disclosed to the defense contained allegations of gambling habits on which she was questioned in cross-examination.

 III

Ringler cites numerous other deficiencies in his trial attorney's representation, including his failure to sequester the complainant, failure to object to questions eliciting inadmissible evidence, failure to oppose an impermissible jury instruction, and failure to request a mistrial.

Ringler argues that because the complainant's allegations of sexual abuse were uncorroborated, she should not have been allowed to sit in the courtroom and listen to opening statements and the testimony of other witnesses prior to her testimony. He further argues that it was professionally unreasonable to allow her to remain in the courtroom without objection after the court and counsel were aware she was making faces and mouthing words such as "bitch" and "liar" to the defense witnesses.

Ordinarily, in criminal cases, the question of sequestration is within the sound discretion of the trial court. Minn. R. Crim. P. 26.03, subd. 7; State v. Gardner, 267 Minn. 97, 112, 125 N.W.2d 591, 601 (1963). But while sequestration is discretionary, "in practice sequestration is rarely denied in criminal cases and rarely should be denied." State v. Posten, 302 N.W.2d 638, 640 (Minn. 1981). Permitting the complainant to be present during opening statements and while other witnesses testified would allow her to respond to Ringler's theory of the case and could allow her to tailor her testimony to that of other prosecution witnesses. Although Ringler's trial attorney may have weighed tactical factors in deciding whether or not to request sequestration, the tactical value is not immediately apparent.

Ringler lists numerous examples of circumstances in which his trial attorney "inexcusably" allowed the prosecutor to introduce inflammatory evidence and failed to object or to request a mistrial. These include the complainant's testimony that (1) "John Wolter taught his daughter sexual intercourse"; (2) "John Benedict taught his daughter intercourse"; (3) "Harold Lucht taught his daughter intercourse"; (4) "Georgia Ringler had a gambling problem"; (5) Ringler and his wife had not had intercourse since 1989; and (6) one of the places Ringler and the complainant "parked" was a favorite of Lucht and his daughter Terry. The statements are all inflammatory and of questionable probative value, but defense counsel could reasonably have decided they diminished the complainant's credibility.

Finally, Ringler contends his trial attorney was ineffective for failing to object to a jury instruction that the testimony of a victim need not be corroborated in a prosecution for criminal sexual conduct. Caselaw supports Ringler's argument that the jury instruction was not appropriate. State v. Williams, 363 N.W.2d 911, 913-14 (Minn. App. 1985) (holding that because lack of corroboration is evidentiary, not substantive, jury instruction improper), review denied (Minn. May 1, 1985). But in the direct appeal Ringler raised the jury-instruction issue, and this court held that the instruction was harmless in light of the entire jury instructions. Ringler, 1998 WL 313584, at *4.

 IV

We now turn to whether trial counsel's professionally unreasonable conduct requires a new trial. We first look to the attorney's conduct in calling Harold Lucht as a witness. Despite the neighbor's statement and the attorney's failure to interview Lucht, Ringler's trial attorney chose to call Lucht to testify about his perceptions of the relationship between Ringler and the complainant. When the state subsequently cross-examined Lucht, it established: (1) Lucht was an employee of the Aitkin County Sheriff's Department and was Ringler's best friend; (2) Lucht made a sexually-laden comment to the complainant to the effect that she was "too hard on Ringler"; (3) Lucht suspected Ringler was having a sexual relationship with the complainant; (4) Lucht discussed his suspicions about Ringler and the complainant with the neighbor; and (5) Lucht provided Ringler with pornographic videotapes for Ringler's son's bachelor party.

This testimony unquestionably prejudiced the outcome of Ringler's trial. See Bolander, 978 F.2d at 1079 (holding defendant convicted of first-degree murder in death of husband received ineffective assistance from trial counsel who did not object to introduction of principal evidence on issue of premeditation, hearsay pretrial statement of wife that defendant had told her he was going to "fix" her husband).

In this case, the evidence of guilt was not overwhelming. It was a question of the complainant's credibility versus Ringler's credibility. No physical evidence was presented, and there were no eyewitnesses. Although the complainant indicated that she and Ringler "regularly" had intercourse on a particular couch, the Bureau of Criminal Apprehension's testing for semen stains on the couch fabric was negative. Other than Lucht's testimony on cross-examination, the only evidence corroborating the complainant's claims was her psychiatrist's diagnosis, which was based on the history she reported to him.

Thus, if the attorney had adequately prepared for the case, we can determine no logical reason he would have put Lucht on the stand. Without Lucht, there would have been little testimony corroborating the complainant's statements, and the testimony of the other defense witnesses would not have been undermined.

Relying on the postconviction court's findings and the transcripts of the trial and the postconviction hearing, we conclude that trial counsel's representation of Ringler was so professionally unreasonable that it has undermined our confidence in the outcome of the trial. But for the trial attorney's errors, there is a "reasonable probability" the result of the trial would have been different on one or all of the charges. Consequently, we reverse and remand for a new trial.

Reversed.

[*] Retired judge of the Minnesota Court of Appeals, serving by appointment pursuant to Minn. Const. art. VI, § 10.