OKLAHOMA CITY (AP) — A preliminary hearing is under way for a man charged with killing a prostitute featured on HBO's "Cathouse" series and three other people in Oklahoma City.

OKLAHOMA CITY (AP) — A preliminary hearing is under way for a man charged with killing a prostitute featured on HBO's "Cathouse" series and three other people in Oklahoma City.

Testimony began Friday in the hearing to determine whether there is enough evidence to try 34-year-old Denny Phillips for first-degree murder in the 2009 deaths that included 22-year-old Brooke Phillips — who worked as a prostitute at Moonlite Bunny Ranch near Carson City, Nev. Denny Phillips — who was not related to Brooke Phillips — has pleaded not guilty.

Police detective Ryan Porter testified that Denny Phillips was linked to the case when police learned a car connected to him was driven to Oklahoma City the day of the killings.

Also killed were 22-year-old Milagros Barrera, 25-year-old Jennifer Ermey and 32-year-old Casey Mark Barrientos.