Nicole Stewart, 33, said she drove that evening to Silverado Drive in Cordelia with the defendants Henry Don Williams, 32, and Gene Allen Combs, 45.
She testified Williams and Combs wanted to confront a drug dealer who owed Combs $50.
The dealer was not home, but as the three were leaving in a Dodge Intrepid, a car passed them and made a U-turn and got behind their vehicle, Stewart said.
She said Williams told her to pull over, and he got out of the car while Combs stayed in the back seat. She said Williams had a black, plastic case about the size of a small purse.
Stewart said she heard shots and Williams got back in the car.
She said she did not see a gun, but saw Williams rubbing something with his shirt.
Garcia was found in the 5000 block of Silverado Drive. He had been shot in the back of the head and died on Sept. 5.
Chief Deputy District Attorney George Williamson is presenting more testimony this morning from Fairfield police officers about the fatal shooting.
