The defendant at the center of an organized crime investigation in San Francisco's Chinatown was set to take the stand for a second day after acknowledging dealing drugs and getting involved in a street gang, but saying he later renounced criminal activity and had nothing to do with a 2006 murder.

Raymond "Shrimp Boy" Chow is expected to again be questioned by his attorneys Tuesday in the racketeering and murder trial against him in federal court.

Prosecutors say Chow had Allen Leung, the leader of a Chinese fraternal group with criminal ties killed, and then took over the group. Chow ran an enterprise that engaged in drug trafficking, money laundering and the sale of stolen cigarettes and alcohol, according to prosecutors.

The lengthy investigation led to the indictment of more than two dozen people and the conviction of a state senator.

Chow said Monday he ran an escort service, dealt cocaine and was involved in a street gang, but upon his release from prison in 1989 for a second time, he got jobs at a supermarket and law office.

Chow testified in English, though it's not his first language and he has used a translator during other court hearings.

Chow was convicted on a federal gun charge in 1995 and released in 2003 after agreeing to cooperate in another prosecution. He said after engaging in meditation, he decided to renounce criminal activity and focused instead on writing his biography.

Chow later said there were rumors in Chinatown that he had killed Leung, but that he was not involved in the slaying.

"I've been waiting for this chance in court to tell everybody I do not kill Allen Leung...," said Chow, his voice rising. "I am innocent on that. That's a fact."

The undercover agent, who testified earlier under the pseudonym David Jordan to protect his identify, said Chow repeatedly accepted money after introducing the agent to money launderers.

The agent spent hours with Chow and people connected to him at fancy restaurants and nightclubs, recording many of their conversations. The case ultimately led to charges against Chow and more than two dozen others in 2014, and the conviction of state Sen. Leland Yee, who pleaded guilty to racketeering in July.