The man on trial for his life for fatally shooting a Prince George's County police officer in a Laurel apartment complex in June was running away when the officer fired first, a key defense witness testified yesterday. The witness, Terri King, testified that she was sitting on the balcony of her apartment about 11 a.m. June 21 when she heard shouting and stood to take a look. King testified that she saw a black man running while holding up his shorts with both hands. Defendant Robert M. Billett, originally from Jamaica, is black. King testified that she heard the words, "Stop or I'll shoot," and saw a white man -- Cpl. Steven Gaughan -- on one or two knees, both arms stretched out in front of him, holding a gun. "He shot twice," King testified under direct examination by Assistant Public Defender Janet Hart. King said she saw the black man -- Billett -- zigzag toward some trees. She said she stepped inside and called 911. The defense contends that Billett shot Gaughan in self-defense after the officer fired first. In her opening statement, Hart said King would be the most important witness in the trial. Prince George's prosecutors are seeking the death penalty against Billett, 44. Gaughan, 41, was a 15-year veteran of the force. He was promoted to sergeant posthumously. The fatal encounter began with an attempted traffic stop. Billett was riding in a Chevy Tahoe that Gaughan's plainclothes police unit wanted to stop. When an officer in a squad car tried to pull over the sport-utility vehicle, the driver, Rohan Patterson, ran two red lights and drove into his apartment complex. Billett hopped out, and Gaughan chased him. Patterson testified for the state that Billett pulled a handgun and threatened to kill him if he stopped for the police. During a shootout with other county police officers, Billett was wounded in the back of a leg, in the back of an arm and in the buttocks, Hart has said. [more]