Authorities say four people have been arrested in connection with a fatal shooting after a fight broke out at a weekend house party in Southern California.

The San Bernardino Sun reported Wednesday that the alleged gunman, 24-year-old Julian Garcia, has pleaded not guilty to assault with a deadly weapon and being a felon in possession of a firearm.

Investigators haven’t said if Garcia knew Nathaniel Shamblin, the 18-year-old man shot early Sunday at the home in Upland. After being struck by gunfire, Shamblin jumped into a car and drove away, but crashed nearby. He died at the scene. A passenger suffered a head injury.

A second man shot at the home suffered critical injuries and a third man had non-life-threatening gunshot wounds.

The newspaper says three women have been arrested on suspicion of being accessories.