Ronald Cosper's fingerprint was found on a screen door in the home where Steve Mosley died.
Yet during the second day of his felony murder trial Wednesday, a jury watched a recorded interview in which Cosper, 21, told investigators he'd never even met Mosley.
"I know that's a lie," investigator Lucas Fuller told Cosper.
During opening arguments Tuesday, prosecutors said Cosper shot Mosley to death during a botched robbery on July 2, 2012. Mosley's attorney said that was impossible, because Cosper wasn't there when Mosley was shot.
When he was brought in by police, Cosper first denied even knowing the man, then said he bought marijuana from him on a few occasions. He said he didn't want to incriminate anyone else, and so had denied knowing Mosley. He finally said he never made it farther than the door of Mosley's Hawthorne Street home.
Much of Wednesday's testimony focused on forensic evidence collected at the scene.
Cosper's fingerprint was found on the front screen door, investigator Steve Pugliese testified. Police found shell casings hidden under Cosper's mattress, but determined the casings weren't connected to Mosley's death. The murder weapon was never recovered.
In the video interview, when Pugliese asked Cosper for a DNA sample, he refused to give it.
Mosley's brother, Michael, also testified Wednesday. He said Steve Mosley had an intellectual disability and attended Orange Grove Center for a time. He had trouble reading and writing, Michael Mosley said, and had a childlike mind. He enjoyed playing video games and marijuana.
"Smoke his weed, play his games, that's all he did," Michael Mosley said.
Mosley's former girlfriend, Cheryl Billups, also testified about the day he was killed. She heard loud booms she thought were fireworks.
"After that went off, I started hearing screams, I started hearing children hollering, I heard people crying 'Help me, help me,'" Billups said.
Minutes later, Billups said, she saw a white car with one white man and two black men pull up in an area between North Hawthorne Street and Sheridan Avenue. One of those men, she said she later learned, was Cosper.
One of the others, she said, was Devante Stoudemire, whom she recognized. Stoudemire is charged in the killing, and Dustin Hayes pleaded guilty to facilitation to commit aggravated robbery in conjunction with Mosley's death last week. He is expected to testify when the trial resumes today.
Contact staff writer Claire Wiseman at firstname.lastname@example.org or 423-757-6347. Follow her on Twitter@clairelwiseman.