Lee Sullivan, 22, entered the plea in San Francisco Superior Court Thursday morning in connection with the June 24 killing of 19-year-old Jaquan Rice at a bus stop near West Point and Middle Point roads.
Sullivan has been charged with murder, attempted murder, aggravated mayhem, possession of cocaine base for sale and other offenses, prosecutors said. He remains in custody on $5 million bail.
Assistant District Attorney Sarah Hawkins said Thursday that Sullivan's case will return to court on Tuesday to link up with those of the other two suspects in the shooting -- Derrick Hunter, 20, and his brother Quincy Hunter, 14, who is being charged as an adult.
The Hunters were arrested in the days after the shooting, and Sullivan was arrested last week, police said.
Police and prosecutors have not disclosed a possible motive for the shooting.
Anyone with information about the case is encouraged to call the Police Department's homicide detail at (415) 553-1145, the department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411 with "SFPD" in the message.