He’s charged in the slaying of Rep. Melissa Hortman and her husband, and the shooting of Sen. John Hoffman and his wife.

Vance Boelter, the suspected assassin accused of gunning down two Minnesota lawmakers and their spouses, killing one couple, is expected to plead not guilty during his arraignment in federal court

It's still unclear whether accused assassin's attorney plans to pursue a mental health defense now that his not guilty plea has been made.