Prince George's County police had a hectic night Thursday as tragic incidents left two persons killed and one seriously injured.

An 18-year-old Clinton man was killed when his car was struck as he ran a red light at the intersection of Branch Avenue and Malcolm Road in Clinton at about 9 p.m., according to police.

The Chevette driven by Dennis O'Neill, of 6601 Oak Orchard Ct., was hit broadside by a pickup truck traveling north on Branch.

O'Neill was pronounced dead at Prince George's General Hospital. Victor D. Fosset 18, of Clinton, a passenger in O'Neill's car, received minor injuries and was in good condition at the hospital yesterday.

Police said the driver of the pickup, William Higgs, 34, of Waldorf, lost control of the truck after the collision and hit two other vehicles. Higgs and the driver of one of the other cars were treated at Southern Maryland Hospital and released.

Also at about 9 p.m., during a dispute in Oxon Hill, Walter A. Boyd, 35, was shot dead in his apartment at 1121 Kennebec St.

Police said that Boyd was arguing with his girlfriend and was shot by the woman's brother. Police arrested the brother, Steve Williams, 29, of 1117 Kennebec St. Williams was jailed without bond.

About three hours later, shortly before midnight, John H. Proctor, 41, was found by his daughter, slumped over the steering wheel of his car in the 3400 block of 23rd Parkway, Temple Hills, according to county police. Proctor, of 2606 Edfeldt Dr. in District Heights, had been sitting in his car and apparently was shot in the head during an attempted robbery, police said.

Proctor and his daughter had been picking up Christmas gifts . Police said Proctor walked his daughter to a house on the street and said that he was going to a store and would return shortly.

Police would not release the daughter's name, but said that when she went to the doorway a short time later to see if her father had returned, she saw his car and began walking toward it with the gifts. She then noticed that her father was slumped over the steering wheel.

Proctor was in critical condition yesterday at Prince George's General Hospital.