OKLAHOMA CITY — The former girlfriend of a man accused of killing four people, including a prostitute featured on HBO’s “Cathouse” series, testified Tuesday she overheard him plan the Oklahoma City shootings because he was unhappy with the amount of money he made from a drug dealer among those killed.Denny Edward Phillips, 34, is charged in the deaths of drug dealer Casey Mark Barrientos and three others, including two pregnant women. One of the victims was Brooke Phillips, who had worked for a legal Nevada brothel featured on HBO. She was not related to Denny Phillips.In testimony at Denny Phillips’ preliminary hearing Tuesday, his former girlfriend testified Phillips and a second man, David Allen Tyner, planned to kill Barrientos, 32, because they were unhappy with their take from Barrientos’ drug trade. “They were going to kill Casey and anybody who was in the house,” Karine Sanders testified in Oklahoma County District Court. “I almost felt threatened by it.”Investigators say Barrientos ran a drug and prostitution ring out of the south Oklahoma City house where the victims were killed. Denny Phillips and Tyner, 31, allegedly were involved in illegal drug sales with Barrientos.Sanders said she dated Denny Phillips during the summer of 2009 and that they frequently visited the house.“It was like a party house,” she said. “A lot of strippers. A lot of drugs. A lot of drinking.”She said there was also a lot of money lying around and that many who visited the house were armed.A resident of the house who survived, Jose Fiero, testified that he saw Tyner walk into the home where the victims were shot but never saw Denny Phillips.Previous testimony indicates that Phillips told a fellow inmate at a federal prison that he was nearby when the victims were killed, but not actually present.Denny Phillips faces six counts of murder because Brooke Phillips, 22, and Milagros Barrera, 22, were pregnant when they were killed. All of the victims, including Barrientos and Jennifer Ermey, 25, were shot and stabbed and their bodies were set on fire. The preliminary hearing, which began last week, will determine whether there is probable cause that Denny Phillips was involved in the shootings and should be tried for murder. It’s scheduled to resume Feb. 26. Denny Phillips has pleaded not guilty to the charges. Prosecutors said Tuesday they will seek the death penalty if he is convicted.Tyner, whom Sanders identified as her cousin, worked as Barrientos’ bodyguard and complained to Denny Phillips that he was not being paid enough, Sanders said. Denny Phillips was also not happy with the amount of money he made from drug deals with Barrientos, she said.“Let’s do something about it,” Sanders testified Denny Phillips said at one point during a conversation with Tyner in which she was present. She said Denny Phillips made it clear that he wanted to personally kill Barrientos.“He wanted to shoot Casey, I know that,” Sanders said. “He said he wanted to look in his eyes.”Sanders said she broke up with Denny Phillips in September 2009, two months before the shootings and did not report the threats because she did not take them seriously.In May 2012, Tyner pleaded guilty to six counts of first-degree murder and was sentenced to consecutive life prison sentences without the possibility of parole in a plea agreement to avoid a possible death sentence. HBO’s “Cathouse” focused on the Moonlite Bunny Ranch near Carson City, Nev. Brooke Phillips left the show two months before her death after becoming pregnant.