MINNEAPOLIS (AP) - A prosecutor told jurors they would see a teen charged with murdering his friend's grandmother confess during a video they planned during trial.

Reports say jurors heard opening arguments Friday in the trial of 19-year-old Brok Junkermeier, accused of choking and stabbing 79-year-old Lila Warwick last July near Willmar.

Junkermeier has pleaded not guilty to allegedly carrying out the ambush robbery and attack prosecutors say he planned with Warwick's grandson, Robert Warwick, now 18.

Junkermeier's attorney Kent Marshall said there is no doubt his client killed Lila Warwick but that doesn't mean that he's guilty of both first-degree murder with premeditation and first-degree murder in the course of a burglary. Marshall declined to elaborate outside the Kandiyohi County Courthouse.

Robert Warwick's trial is not yet scheduled.