DENVER - The estranged husband of a woman savagely murdered in a parking garage along with her would-be rescuer killed himself yesterday when police pulled him over in the Mojave Desert.

Duncan Cameron, driving a rental car with a loosely attached New Mexico license plate, shot himself after California Highway Patrol officers pulled him over in Southern California.

After the apparent suicide, Denver officials said the prosperous Denver lawyer had been the sole suspect in his wife's murder.

''He was the focus of the investigation,'' said Denver District Attorney Bill Ritter. ''There were no other suspects.''

After he was pulled over in the desert near Barstow, Calif., and asked for his identification, Cameron produced a birth certificate. Then he grabbed a pistol from beneath his seat, put the gun in his mouth and pulled the trigger, said CHP spokesman Willie Hailey.