A Cobb County judge set a trial date Monday for the man accused of shooting five of his former co-workers, killing three, at a Penske trucking facility more than three years ago.

But lawyers also filed motions Monday, contending that accused gunman Jesse James Warren was insane at the time of the Jan. 2010 shootings isn't competent to stand trial, Channel 2 Action News reported.

Still, Judge Mary Staley told both sides the trial will start May 28.

Warren, 63, of Temple, allegedly was wearing camouflage and had two handguns when he fired multiple shots inside the Penske facility at 3011 Barrett Lakes Boulevard, near the intersection of Chastain Road, shortly before 2 p.m. on Jan. 10, 2010. Warren was arrested nearly a mile away, at the intersection of McCollum Parkway and Duncan Road after he left the scene in a red Chevy S-10 truck.

Jaider Felipe Marulanda, 43, of Lawrenceville; and Penske employees Robert Gonzalez, 31, of Dallas, Ga., and Vance Springer, 59, of Woodstock, were killed in the shootings. Two other employees were critically injured.

Warren worked for Penske as a truck mechanic from June 2005 through July 2009, a company spokesman previously said. He has remained in the Cobb County jail without bond since his arrest and could face the death penalty.