State of Minnesota, City of Eagan, Appellant, vs. Byron Gale Nesseth, Respondent.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1998).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C8-98-1058
 C2-98-1069

State of Minnesota,

Respondent,

vs.

Pauline Agnes Wilson,

Appellant,

Renee Julia Judkins,

Appellant.

 Filed May 4, 1999

 Affirmed

 Amundson, Judge

Cass County District Court

File Nos. K997624 and K097625

Mike Hatch, Attorney General, Joseph F. Henderson, Nancy J. Bode, Assistant Attorneys General, 445 Minnesota Street, Suite 900, St. Paul, MN 55101; and

Earl Maus, Cass County Attorney, P. O. Box 3000, Walker, MN 56484 (for respondent)

John M. Stuart, State Public Defender, Bradford Delapena, Assistant State Public Defender, 2829 University Avenue Southeast, Suite 600, Minneapolis, MN 55414 (for appellants)

Considered and decided by Amundson, Presiding Judge, Anderson, Judge, and Holtan, Judge.[*]

 U N P U B L I S H E D O P I N I O N

 AMUNDSON, Judge

This appeal is from judgments of conviction entered against appellants Pauline Wilson and Renee Judkins for gross misdemeanor obstructing legal process in violation of Minn. Stat. § 609.50, subs. 1(2), 2(1) (1998). Wilson was also found guilty of fifth-degree assault. Minn. Stat. § 609.224, subd. 1(2) (1998). Because we conclude the trial court did not abuse its discretion in its evidentiary rulings and jury instructions, nor deny appellants their right to present a defense, we affirm.

 FACTS

Appellants Wilson and Judkins were charged with gross misdemeanor obstructing legal process and fifth-degree assault for attacking Officer Robert Karbowski on June 21, 1997, after he stopped the vehicle Wilson was driving on the Leech Lake Reservation for expired license tabs. At the scene, Wilson and Judkins challenged Officer Karbowski's authority to enforce traffic laws on the reservation.

At the omnibus hearing, appellants moved to dismiss the charges on the grounds that Officer Karbowski did not have jurisdiction to make the stop. The trial court denied the motion. Officer Karbowski testified that he was on patrol when he saw a van with expired Georgia license plates. He could not tell who was in the van or whether they were Native Americans. As soon as he had stopped the van, however, two Native American women got out and started towards him, yelling that he had no jurisdiction to stop them. On cross-examination, defense counsel asked Officer Karbowski if he knew he lacked authority to enforce certain laws on the reservation. The prosecutor objected to the question and the court sustained the objection.

Wilson testified Officer Karbowski stopped them because of the loud music emanating from the van. She testified that Judkins raised the jurisdictional issue with Officer Karbowski. Judkins testified she had done so and, "talked to him about the Stone decision." When defense counsel asked Judkins the basis for her statement to Officer Karbowski, however, the trial court sustained the prosecutor's objection.

The trial court rejected the defense request for a jury instruction defining Officer Karbowski's "official duties" in terms of the state's jurisdiction on the reservation.

In closing argument, defense counsel discussed appellants' challenge at the scene to Officer Karbowski's authority. When counsel discussed Officer Karbowski's "official duties," however, and noted "questions raised" about the officer's duties on the reservation, the court sustained the prosecutor's objection.

The jury convicted both Wilson and Judkins of obstructing legal process "with force or violence," and convicted Wilson of fifth-degree assault.

 D E C I S I O N

Appellants argue that the trial court denied them their right to present a defense, and effectively directed a verdict against them, when it excluded defense evidence, and rejected any jury instruction, concerning Officer Karbowski's jurisdiction, and the scope of his "official duties," when they resisted him.

This court reviews a trial court ruling on the admissibility of evidence under an abuse of discretion standard. State v. Kelly, 435 N.W.2d 807, 813 (Minn. 1989). The refusal to give a requested jury instruction is also reviewed under an abuse of discretion standard. State v. Blasus, 445 N.W.2d 535, 542 (Minn. 1989). This court reviews a legal determination, such as the state's jurisdiction on the reservation and its relation to an officer's "official duties," de novo. See State v. Bunde, 556 N.W.2d 917, 918 (Minn. App. 1996) (applying statutory criteria to the facts found is a legal question requiring de novo review).

The trial court concluded that the jurisdictional issue appellants sought to present to the jury was a legal issue that had already been decided by the court in its omnibus order. We agree. Jurisdiction is a legal issue for the court's determination. See generally V.H. v. Estate of Birnbaum, 543 N.W.2d 649, 653 (Minn. 1996) (holding that a determination of whether personal jurisdiction exists is a question of law).

Appellants were charged with obstructing Officer Karbowski "while the officer [was] engaged in the performance of official duties." Minn. Stat. § 609.50, subd. 1(2) (1996). Whether the officer is engaged in "official duties" is a question of fact for the jury to decide, but the jury should not be asked to decide whether an officer was performing "proper" official duties, as defense counsel phrased it at trial.

Appellants cite no case law holding that officers acting outside or beyond their jurisdiction are no longer performing "official duties." The supreme court held that a police officer who follows a motorist outside the officer's jurisdiction while on duty is acting in the course and scope of employment and may make an investigative stop. State v. Tilleskjor, 491 N.W.2d 893, 894 (Minn. 1992). This court held that on-duty police officers may "operate free from the limitations of their city borders when the policing mission itself commences within the city * * *." Bunde, 556 N.W.2d at 919. Minnesota courts have recognized that police officers charged with the duty to prevent crime and enforce the laws must be accorded a wide degree of discretion. Duellman v. Erwin, 522 N.W.2d 377, 379-80 (Minn. App. 1994), review denied (Minn. Dec. 20, 1994). Appellants' reading of the statute, however, would have the opposite effect, stripping officers of their authority, and allowing citizens to obstruct their efforts, if the officers made an error in legal judgment as to their jurisdiction.

The state's jurisdiction to enforce traffic laws against tribal members on the reservation was far from clear at the time Officer Karbowski stopped appellants' vehicle. See generally State v. Jackson, 558 N.W.2d 752, 755 (Minn. App. 1997) rev'd, 570 N.W.2d 503 (Minn. 1997) (holding that because defendant was not subject to tribe's motor vehicle code the state could enforce proof-of-insurance statute on the reservation); cf. State v. Stone, 557 N.W.2d 588 (Minn. App. 1996) aff'd, 572 N.W.2d 725 (Minn. 1997) (holding some traffic laws, including proof-of-insurance statute and expired registration law, were civil/regulatory laws that state could not enforce on reservation). As of June 1997, review had been granted in Jackson and Stone, but the supreme court had not yet spoken. The supreme court ultimately clarified this issue in an opinion issued long after the stop. See Stone, 572 N.W.2d at 731 (holding that expired license registration, among other state traffic-related laws, could not be enforced on a reservation). The legal issue appellants claim should have been presented to the jury is neither simple nor amenable to jury resolution.

A defendant is not entitled to submit evidence that is not relevant or is otherwise inadmissible. State v. Hanninen, 535 N.W.2d 660, 661 (Minn. App. 1995). Similarly, a defendant's requested jury instruction need not be given if it is not supported by the evidence or by the relevant case law. State v. Ruud, 259 N.W.2d 567, 578-79 (Minn. 1977). The trial court did not abuse its discretion in excluding defense evidence or denying the proposed jury instruction on the legal issue of state jurisdiction.

We also conclude that the trial court's rulings did not violate appellants' right to present a defense. A criminal defendant has a due process right to explain his conduct to the jury. State v. Brechon, 352 N.W.2d 745, 751 (Minn. 1984). Appellants, however, were allowed to explain their conduct, in resisting Officer Karbowski's authority. There was no objection to that testimony by the prosecutor, who even elicited from the officers some of what appellants said to Officer Karbowski concerning his alleged lack of jurisdiction.

Appellants have submitted a supplemental pro se brief challenging the credibility of various prosecution witnesses, raising a new issue of ineffective assistance, and relying on facts not in the record. This court, however, must defer to the jury's finding on credibility, and cannot consider matters not presented to the trial court. State v. Bliss, 457 N.W.2d 385, 390 (Minn. 1990) (holding that the credibility of individual witnesses is for the jury to determine); State v. Morrow, 492 N.W.2d 539, 549 (Minn. App. 1992) (noting that appellate court may not base decision on matters outside the record on appeal).

Affirmed.

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