"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.

Siliman had a wife and two children in Africa, one a baby boy he had never met. He was in the process of getting his family to America when he was killed.

"The victim was living the American dream, as all of us aspire to do," Rionda said. "And this is a classic example of someone who does that, and then you've got a defendant taking advantage of that and seeing an easy prey and brutally and savagely murdering him."