GRANITE FALLS (AP) - Prosecutors have refused to hear a Minnesota man's offer to plead guilty in the shooting deaths of his ex-girlfriend and another man.

Instead, prosecutors plan to convene a grand jury in the case.

Twenty-eight-year-old Andrew Dikken of Renville had intended to plead guilty Wednesday to two counts of second-degree murder.

But because the prosecution plans to convene a grand jury, the judge would not hear Dikken's plea offer.

A grand jury is required in Minnesota to bring an indictment for first-degree murder.

Dikken is charged in the shooting deaths last month of 26-year-old Kara Monson and her 28-year-old boyfriend, Chris Panitzke.  The victims were shot in Monson's Granite Falls home. Monson died at the scene and Panitzke died days later at HCMC.