Wichita ? Two suspects in the death of a former Kansas police officer will go to trial May 31.

Michael Williams and Deborah Weiss pleaded not guilty Thursday to first-degree murder in the death of Sean Putnam, who was their roommate.

The 41-year-old Putnam’s body was found in February in a shallow grave in the back yard of a Wichita home. Prosecutors say he was shot to death in late December

During a preliminary hearing Thursday, witnesses testified that Williams said he shot Putnam after an argument, and Weiss was accused of tying a cord around Putnam’s neck after he was shot.

The Wichita Eagle reports that Putnam worked as a law enforcement officer in Bel Aire, Galena and Cherokee County. When he died, he was working as a roofer.