SANTA ROSA — Santa Rosa police have arrested one of two suspects in a stabbing assault that occurred last month, a police sergeant said today.

An 18-year-old man suffered critical but not life threatening injuries when he was stabbed April 7 in a crowded shopping center parking lot across the street from Santa Rosa Junior College on Mendocino Avenue, Sgt. John Cregan said.

The victim was getting out of a parked vehicle when his door accidentally struck the side of another vehicle parked next to him, Cregan said.

Two white males got out of the car and confronted the victim, shouted gang challenges and made gang hand signs, Cregan said. One of the suspects stabbed the victim once in the abdomen and both suspects then fled in a black Dodge Charger, Cregan said.

Police said the victim has no known gang association.

Police obtained arrest warrants for Adam John Thomas, 30, and Gerald William Hess Jr., 34, both of Santa Rosa for felony assault with gang enhancements. Both men are well-documented gang participants with numerous law enforcement contacts, and Thomas was on felony probation for transporting marijuana, Cregan said.

Police found the Charger that was registered to Thomas, who turned himself in Tuesday in Sonoma County Superior Court, Cregan said.

Thomas was arrested and booked under a no bail hold in the Sonoma County jail for assault and a probation violation, Cregan said.

Hess is still at large. He is described as a white male adult, 5 feet 11 inches, 190 pounds with blond hair and blue eyes. Hess has “CALIF PRIDE” tattooed across his left shoulder, Cregan said.