State of Minnesota, Respondent, vs. Robert Irwin Greenberg, Appellant.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C1-97-1201

State of Minnesota,

Respondent,

vs.

Pierre Joseph Poisson,

Appellant.

 Filed March 31, 1998

 Affirmed and motion denied

 Schumacher, Judge

Isanti County District Court

File No. K8961342

Hubert H. Humphrey III, Attorney General, Catherine M. Keane, Assistant Attorney General, 1400 NCL Tower, 445 Minnesota Street, St. Paul, MN 55101; and

Jeffrey R. Edblad, Isanti County Attorney, 555 18th Avenue Southwest, Cambridge, MN 55008 (for respondent)

John M. Stuart, State Public Defender, Evan W. Jones, Assistant Public Defender, 2829 University Avenue Southeast, Suite 600, Minneapolis, MN 55414-3230 (for appellant)

Considered and decided by Shumaker, Presiding Judge, Huspeni, Judge, and Schumacher, Judge.

 U N P U B L I S H E D O P I N I O N

 SCHUMACHER, Judge

Appellant Pierre Joseph Poisson challenges his conviction for theft and receiving stolen property, arguing that the trial court abused its discretion by admitting three prior burglary convictions as impeachment evidence. He also claims ineffective assistance of counsel, perjured testimony, and juror bias. We affirm.

 FACTS

Poisson was charged with three counts of theft, two counts of receiving stolen property, and obstructing legal process. He and his friends were alleged to have stolen three snowmobiles from a sports store. Although Poisson maintained that he had no involvement in the incident, he did admit at trial that he had been with his friends when they were initially planning the theft. At trial, the prosecution sought to impeach Poisson with his convictions of eight felonies and a misdemeanor. Poisson objected to admission of three 1985 burglary convictions. The court excluded two of Poisson's prior convictions, but admitted all others, including the three 1985 burglary convictions. The court found the probative value of the burglary convictions outweighed the prejudicial effect.

The jury found Poisson guilty of two counts of theft and two counts of receiving stolen property. The trial court sentenced Poisson to 75 months in prison, an upward durational departure of 31 months, pursuant to the career offender statute, Minn. Stat. § 609.152, subd. 3 (1996). Poisson challenges the admission of his prior burglaries as impeachment evidence. He also filed a pro se brief. The state moved to strike the pro se brief on the grounds that it raised issues Poisson had not raised to the trial court and included facts outside of the record on appeal.

 D E C I S I O N

Poisson argues the admission of the 1985 burglary convictions was prejudicial to his case and warrants a new trial. The trial court's evidentiary decisions will not be overturned absent an abuse of discretion. State v. Brouillette, 286 N.W.2d 702, 707 (Minn. 1979).

Minn. R. Evid. 609 governs the admissibility of prior convictions for impeachment purposes. The general rule allows admission of a prior conviction only if (1) the crime was punishable by imprisonment in excess of one year and the court determines the probative value of the evidence outweighs its prejudicial effect or (2) the prior crime involved dishonesty or false statement. Minn. R. Evid. 609(a). Poisson's prior felony convictions meet the requirement of section (1) because they were punishable by imprisonment for more than one year.

Poisson contends the prior convictions were inadmissible because they were over 10 years old. Minn. R. Evid. 609(b) provides:

Evidence of a conviction under this rule is not admissible if a period of more than ten years has elapsed since the date of the conviction or of the release of the witness from the confinement imposed for that conviction, whichever is the later date, unless the court determines, in the interests of justice, that the probative value of the conviction supported by specific facts and circumstances substantially outweighs its prejudicial effect.

The court measures the staleness of a prior conviction by looking at the time that elapsed between the prior date of conviction or release from confinement and the date of the present charged offense. State v. Ihnot, ____ N.W.2d ____ (Minn. Mar. 26, 1998) (holding prior conviction was not stale where only eight years elapsed between date of defendant's release from confinement for prior conviction and date of his present charged offenses).

Poisson's argument against admission of his 1985 prior convictions fails. Those convictions resulted in an executed sentence commencing July 18, 1985, for a 36-month commitment to the commissioner of corrections. Less than 10 years had passed between his release from incarceration on the burglary convictions and the theft of the snowmobiles on December 14, 1996. Thus, Poisson's 1985 burglary convictions were not stale for impeachment purposes. Id.

Furthermore, the trial court found that the probative value of the prior convictions outweighed any prejudice. Trial courts have broad discretion in determining whether a conviction is admissible under rule 609(a). State v. Gassler, 505 N.W.2d 62, 67 (Minn. 1993). In determining admissibility, the court must evaluate these factors: the impeachment value of the prior conviction; the date of the conviction and defendant's subsequent history; the similarity between the past crime and the crime charged; the importance of defendant's testimony; and the centrality of the credibility issue in the case. Id.

Impeachment by the use of prior convictions assists the jury in judging the credibility of a witness. State v. Lloyd, 345 N.W.2d 240, 247 (Minn. 1984). As Poisson argues, the outcome of this case depended on the credibility of the witnesses. We defer to the jury's opportunity to view witnesses and weigh credibility. State v. Washington, 521 N.W.2d 35, 42 (Minn. 1994). Since the time of the prior convictions, Poisson has continuously been in trouble with the law. See Gassler, 505 N.W.2d at 66 (when balancing probative with prejudicial value of prior conviction, court must consider defendant's history since prior conviction). Poisson's string of prior convictions, for burglary and other offenses, demonstrates his pattern of criminal activity.

Although the prior burglary convictions were similar to the present charge, that similarity did not require exclusion of the evidence. Id. at 67. We also note that the likelihood of prejudice was diminished by the fact that neither attorney referred to the prior burglary convictions in closing arguments.

Finally, the admission of the prior burglary convictions did not prevent Poisson from testifying on his own behalf. Cf. id. (court may exclude impeaching evidence if its admission would dissuade defendant from testifying and defendant's testimony is centrally important to case). When a defendant testifies, and his credibility is a main issue in the case, a significant need arises for admission of impeachment evidence. Id. Because Poisson's case rested on his credibility, admission of the prior convictions as impeachment evidence appears to have been necessary.

Having considered these factors, and having given due deference to the trial court's exercise of discretion in this evidentiary ruling, we conclude that admitting the impeaching evidence was not an abuse of discretion.

In his pro se brief, Poisson raises three additional grounds for a new trial: ineffective assistance of counsel, alleged perjured testimony from witnesses, and juror bias. The state moved to strike the pro se brief because it raises new issues not presented to the trial court for decision and includes facts that are outside of the record.

Generally, this court does not consider issues for the first time on appeal. State v. Sorenson, 441 N.W.2d 455, 457 (Minn. 1989). Nor do we consider facts that are not included in the trial court record. Minn. R. Civ. App. P. 110.01 (record on appeal includes papers filed in trial court, exhibits, and transcripts); Minn. R. Crim. P. 28.02, subd. 8 (same). This court may consider arguments for the first time on appeal, however, when the interests of justice require it and neither party would be unfairly surprised. Sorenson, 441 N.W.2d at 457. This court gave the state permission to file a responsive brief addressing Poisson's new issues. To give Poisson a full hearing, we accept his pro se brief, but strike the facts that are not part of the record.

In order to establish ineffective assistance of counsel, Poisson needed to show that his attorney's representation did not meet "an objective standard of reasonableness" and that, but for the attorney's ineffectiveness, the case would have turned out differently. Strickland v. Washington, 466 U.S. 668, 688, 694, 104 S. Ct. 2052, 2064, 2068 (1984); Gassler, 505 N.W.2d at 70. Poisson has not met this high standard of proof.

Regarding Poisson's claim of perjured testimony, a new trial is appropriate when the court is reasonably sure that a material witness testified falsely, the jury would have reached a different conclusion without the perjured testimony, and the defendant was taken by surprise and could not respond at trial. State v. Caldwell, 322 N.W.2d 574, 584-85 (Minn. 1982). Poisson has not met this standard of proof. His allegations of discrepancies between witnesses' testimony are not sufficient to prove perjury. The jury was the ultimate judge of witness credibility. See Washington, 521 N.W.2d at 42 (when defendant alleged perjured testimony, court deferred to jury's opportunity to view witnesses' direct- and cross-examination and weigh credibility).

Finally, to establish juror bias, Poisson must show the juror in question was subject to a challenge for cause and that the juror's presence on the jury actually prejudiced Poisson. State v. Barlow, 541 N.W.2d 309, 312 (Minn. 1995). Again, this claim fails because he has not established these elements.

  Affirmed and motion denied.