Updated

Oklahoma prosecutors on Thursday charged a second man with killing a prostitute featured on HBO'S "Cathouse: The Series" and three other people.

Denny Edward Phillips faces six counts of first-degree murder for the 2009 shooting deaths of Brooke Phillips, 22, who had worked as a prostitute at the Moonlite Bunny Ranch, a legal brothel near Carson City, Nevada; Milagrous Barrera, 22, Jennifer Ermey, 25, and Casey Mark Barrientos, 32. The two additional murder charges are because Brooke Phillips and Barrera were pregnant.

The victims were found inside a burning home in southwest Oklahoma City. Phillips, who was not related to Brooke Phillips, faces an additional charge of conspiracy to commit murder.

Oklahoma County District Attorney David Prater said he plans to seek the death penalty.

"We believe he ordered the hit on Casey Barrientos," Prater told The Associated Press. The others were killed to eliminate witnesses to Barrientos' slaying, the prosecutor said.

Officials with the public defender's office in Oklahoma County, which was appointed to represent Phillips, did not immediately return a phone call seeking comment.

Phillips, 34, is currently in federal prison in Terre Haute, Indiana, after pleading guilty to charges related to an April 2010 shootout in Tulsa in which he was shot three times after allegedly pointing a weapon at officers.

A motive for the Oklahoma slayings was not clear, but drugs appear to have been involved, Prater said.

"We believe there was some bad blood between Phillips and Barrientos," Prater told AP. "Apparently over narcotics, possibly money owed for narcotics."

In May, David Allen Tyner was sentenced to life in prison without the possibility of parole after pleading guilty to six first-degree murder charges in the case. The plea agreement allowed Tyner, 30, to escape a possible death sentence.