The Pittsburg man who allegedly killed East Palo Alto community activist David Lewis pleaded not guilty Friday to murder and related charges, according to the San Mateo County District Attorney's Office.

Prosecutors say Gregory Elarms, 60, followed Lewis to the Hillsdale Shopping Center in San Mateo on June 9, 2010, and shot him as he was getting out of his car in the parking lot. The murder charge is enhanced because Elarms, a convicted felon, used a gun and was lying in wait.

Lewis, 54, was an ex-con and former drug user who later turned his life around and tried to help other people do the same. In 1992, he co-founded a drug treatment center in East Palo Alto called Free at Last. He had known Elarms from childhood.

On Friday, Elarms indicated he wants to fire his public defender, Jonathan McDougall, said Chief Criminal Deputy District Attorney Karen Guidotti. A hearing on that motion was set for 9 a.m. Friday .The case is scheduled for trial on Oct. 29.

Email Bonnie Eslinger at beslinger@dailynewsgroup.com; follow her at twitter.com/ bonnieeslinger.