Omar Cash claims to have scored a 1350 on his SAT exam.

It would take a genius, however, to square his story with that of prosecutors, who maintain that Cash carjacked a Philadelphia couple outside a club two years ago, shot the man to death, and kidnapped and raped the man's girlfriend.

Cash, 28, of Philadelphia, took the stand Tuesday in Bucks County Court, where he is on trial for his life in the May 11, 2008, slaying of Edgar Rosas-Gutierrez and the repeated rape of his girlfriend.

Appearing relaxed and animated, Cash denied abducting, killing, or raping anyone.

He admitted having had sex with the woman at a motel in Lawrence, N.J., shortly after Rosas-Gutierrez was shot execution-style along an exit-ramp embankment in Bensalem.

He acknowledged that security video had captured him arriving at the motel with the woman. And that the camera later caught the woman fleeing from him, clambering frantically over the check-in desk to get away.

Cash did not dispute that his DNA was found on the woman's body. Or that he had fled from the motel to New York City, where he and the victims' car were later found by police.

His explanation, Cash said, is that the woman was a prostitute a friend had arranged for him to meet at the motel. The friend, he said, had arrived in a black Buick Regal that police say belonged to Rosas-Guterriez' uncle.

Cash said he had gotten to the motel by taking a $75 cab ride from a Philadelphia strip club. The woman ran from him, he said, because he had just discovered she had taken money from him while he was showering in the motel room.

Cash testified that he had driven to New York in part because he knew that Philadelphia police had a warrant for his arrest on an unrelated crime.

"I don't know nothing about no murder," Cash testified. "I didn't rape no one . . . I don't know nothing about any of that."

Yet in repeated interviews with police, Cash boasted of his intelligence - claiming a 1350 SAT score, among other things - but never gave the account that he now says should exonerate him.

"At no point did you tell them this story that you told us today?" Deputy District Attorney Marc Furber asked him.

"They didn't care what I had to say," Cash said. "I had the truth and I tried to tell them . . . They didn't want to hear nothing else."

Police say that Cash was lurking in a nearly deserted parking lot when Rosas-Gutierrez and his girlfriend left Jalapeno Joe's, a nightclub on Castor Avenue. Witnesses saw him there and at a nearby Wawa store.

Cash carjacked the couple at gunpoint, robbed them, raped the woman in the back seat, and then shot Rosas-Gutierrez to death on a muddy embankment off of Street Road in Bensalem, authorities say. He is accused of raping the woman twice more before she escaped from him at the motel where he had driven in the Buick.

The woman, whose name is not being published because of the nature of the crime, testified last week.

Cash said that he had been at a strip club in Philadelphia when the club manager asked him to drive with one of the dancers to her car. He said he then had driven past Jalapeno Joe's and visited the nearby Wawa, but never went inside the club.

But he said he did encounter an acquaintance there whom he described as a pimp, and asked that man if he could get him a prostitute. He said the acquaintance arranged to bring the woman to meet him at the New Jersey motel, where the pimp left the black Buick and the keys before leaving in another car.

Closing arguments are expected Wednesday.

If Cash is convicted of first-degree murder, the trial will enter a penalty phase in which jurors will be asked to sentence him either to death or to life in prison.

Contact staff writer Larry King at 215-345-0446 or lking@phillynews.com.