STANTON : Man Fatally Stabbed at Anti-Drug Clinic

An argument, possibly over a woman, turned fatal Thursday when a man stabbed another in the upper torso in the parking lot of a drug-rehabilitation clinic, authorities said.

The victim, whose name was not released pending notification of his relatives, was pronounced dead at UCI Medical Center in Orange shortly after the 10 a.m. attack.

Mark Dennis Matthews, 42, of Anaheim was arrested on suspicion of murder, Lt. Richard J. Olson of the Sheriff’s Department said, adding that the fight apparently was over a woman.

There were several witnesses to the stabbing, but it was not known if the woman was among them, Olson said.

After the stabbing, Matthews left the scene and went home.

“A short time later ,the suspect called police to turn himself in,” Olson said.

Investigators were trying to determine whether either of the combatants or the woman they were thought to be fighting over were seeking treatment at the Western Pacific Stanton Medical Clinic.

The clinic, at 10751 Dale St., treats heroin addicts with methadone, a synthetic narcotic drug used to wean users from heroin.