A Duval County jury is hearing the murder trial of a 33-year-old man accused of fatally beating a 37-year-old Sudanese immigrant last September.

Prosecutors said Merlin Williams Jr., 33, and his girlfriend went to Isaac Siliman's Southside apartment to rob him. Investigators said Ashley Jerrell, 24, pepper-sprayed the victim while Williams tried to use a Taser gun on him.

According to police reports, Jerrell admitted she struck Siliman several times in the head with a hammer before they took his credit cards and left in Siliman's SUV.

Jerrell arranged with prosecutors to plead guilty to second-degree murder, armed robbery and auto theft in exchange for her testimony against Williams.

In an interrogation recording played in court Thursday, Williams could be seen on video for more than an hour avoiding detectives questions, changing his story and offering vague descriptions in Siliman's slaying.

"I know you aren't feelin' me right now," Williams told detectives in the video.

"No, we're not," a detective said.

On the video, Williams admitted that he was inside Siliman's apartment at the time of his death, but initially, he said he was outside smoking a cigarette and his girlfriend, Jerrell, attacked and overpowered Siliman and eventually beat him to death.

"All I know is I grabbed her wrist to get the weapon out of her hand," Williams said. "I was scared. I can't express that enough. I was afraid, and I had nothing to do with it."

The investigators on the video don't believe his story. At one point, they told Williams that Jerrell has already confessed to the slaying, and according to her, the killing was a robbery "gone wrong."

At one point they brought Jerrell into a small room.

"If you just tell them the truth. They asked me the same questions, and I told them from A to Z," Jerrell told Williams on the video.

"They're telling me that I murdered him. I killed him," Williams said.

"We. It wasn't just on you. And I told you guys that, right? I said we," Jerrell said.

Williams eventually admitted to going to Siliman's apartment with the intention of robbing him, and Williams confessed to getting into a fight with the man and trying to use a Taser gun on him.

"The part of him getting hit across the head was nothing that I planned," Williams said.

"And I believe that," a detective told him.

"How many times did you hit him?" another detective asked Williams.

"I didn't hit him," Williams said.

Siliman's family said he was a member of the Lost Boys of Sudan -- refugees who fled the civil war in their home country -- and had recently become a U.S. citizen.