JACKSONVILLE, Fla. -- The prosecution's key witness in the manslaughter trial of a man in the death of a 12-year-old boy -- the victim's best friend -- testified Wednesday that he was with Tony Youmans when he bought a gun and when he raised it to his head and pulled the trigger.

Larry Brown, known as L.J., is the son of Derrick Glover's girlfriend. Glover is accused of selling Tony Youmans a handgun with which the boy killed himself last July.

On the stand for several hours, Brown told the court he was the only person there when Youmans shot himself while playing with the gun he had just bought from Glover.

"He said he was going to pull the trigger twice," Brown said. "The first time he did and nothing happened, and he looked at me and I looked at him. Then he did it a second time. It went off."

With tears streaming down his cheeks, Brown continued.

"I put my hands on his chest and starting calling him and he didn't say nothing," Brown said.

Brown told the jury that Youmans bought the gun from Glover, and said he even confronted Glover about selling his friend the gun.

"I was like, 'Why'd you sell the gun to Tony?' He was like, 'Because you're mom told me to get rid of it.' I was like, 'She didn’t tell you to sell it to him,'" Brown said.

He said after Youmans died, he grabbed the gun a brought it back to Glover.

"I thought Derrick was going to try to get him some help or something, but he didn’t," Brown said.

He said Glover told him he would get in trouble, so they made up a story about seeing Youmans last with three boys.

The defense team, which said in opening statements that Glover was a "patsy" for Brown and his 19-year-old brother, aggressively cross-examined Brown in the afternoon, saying the boy was telling all lies.

They showed the jury video after the video of Brown telling police officers different stories, and asked the boy about statements he made to his brother, asking "why would somebody want to kill Tony?"

"Ain't nobody know about it but me and Derrick," Brown said.

During cross-examination, the defense pointed out many inconsistencies and grilled Brown about how Youmans died.

Attorney: "Didn't you tell him that you came in and told Derrick Glover that you shot Tony?"

Brown: "No."

Attorney: "You're telling us that you have done absolutely nothing wrong. Is that right?"

Brown: "No I'm not. It was wrong to leave him out there. I did that."

Brown later admitted to lying to the jury when prosecutors asked him about a bag they said had money in it and was exchanged with Glover. Brown said it was purple Crown Royal bag, but when cross-examined he said he never really saw the purple bag and admitted that he read about the bag in the newspaper.

Brown has already admitted to lying to police during his initial interview with detectives.

Youmans was reported missing on July 28, 2007 -- two days before his body was found about one mile from his house. Investigators had said he died of a gunshot wound to the head and had powder burns on his hand, but they never released information about how the shot was fired.

Glover has been held without bond since the day Youmans' body was found.

This is the first of two trials for Glover. This trial is for manslaughter and furnishing a firearm to a minor. He is set to be tried next week on two counts of possession of a firearm or concealed weapon by a juvenile.

A jury of six and two alternates was seated on Monday despite the defense's objection that pretrial publicity in the case would not allow a fair trial in Jacksonville.