OKLAHOMA CITY—A former Marine accused in the deaths of a prostitute featured on the HBO reality series “Cathouse” and three others has a new trial date.

David Allen Tyner will go on trial April 9. Oklahoma County Assistant District Attorney Suzanne Lavenue says District Judge Glenn Jones rescheduled Tyner’s trial because a defense witness wasn’t available for his earlier March 12 trial date.

Tyner is charged in the Nov. 9, 2009, deaths of 22-year-old Brooke Phillips and three others at a house in south Oklahoma City. Phillips was a prostitute at the Moonlite Bunny Ranch brothel near Carson City, Nev., that was featured on HBO.

Tyner faces six counts of first-degree murder because Phillips and another victim were pregnant. He has pleaded not guilty.

Prosecutors are seeking the death penalty.