SAN DIEGO -- A young man accused of involvement in three shootings, including one that killed an 18-year-old in Logan Heights, pleaded not guilty Friday to a murder charge and two counts of shooting into an occupied vehicle.

David S. Flores, 20, was ordered held on $1.5 million bail. He faces life in prison if convicted, said Deputy District Attorney Frank Jackson.

The prosecutor told Judge David Szumowski that Flores cut off another car on the freeway April 1, allowing passengers in his car to shoot at the occupants of the other vehicle. No one was injured.

On Monday, Flores allegedly was behind the wheel during a pursuit of another car on state Route 94, during which two of his passengers shot at people in the other vehicle. No one was hurt, the prosecutor said.

About an hour later, Flores and his associates found a rival in the 800 block of South 30th Street, and an alleged gang member who was riding with the defendant shot the victim in the head, the prosecutor alleged.

Martin De la Torre, 18, died at the scene.

Police are still searching for two people allegedly involved in the fatal shooting, Jackson said.

The judge ordered Flores back to court May 29 for a status conference.