Stephen Kinzey used his experience riding his Harley-Davidson to teach about motion and physiology. He researched the effects of video games on the health of children. And he chatted with his students about being a father and a devoted Catholic.

That was Stephen Kinzey, tenured kinesiology professor at Cal State San Bernardino.

But police said they know of another Stephen Kinzey, one who calls himself Skinz.

This is the person who wore leathers and ran the local Devils Diciples motorcycle gang. He stashed guns and bricks of meth inside his tidy suburban Highland home, police say. He fired off text messages to dealers: "Bring whatever cabbage u got for my soup cuz ingredients are low."

Skinz, however, remains a mystery to Kinzey's friends and students. Even to his family.

"This has to have an explanation. He's a PhD," his father, Hank Kinzey, said shortly after his son was implicated. "Something knocked him off course."

In September, Kinzey, 45, was charged with drug dealing, running a street gang and possessing illegal firearms. His girlfriend, former Cal State San Bernardino student Holly Robinson, is accused of helping him run a handful of meth dealers in what law enforcement officials saw as a budding, small-time drug operation.

Until his arrest, Kinzey's worst run-in with police was for a traffic ticket in Bullhead City.

But Kinzey appears to have cultivated a double life for years.

While chairing the Kinesiology Department's curriculum committee, Kinzey was selling Devils Diciples T-shirts on E-Bay. He created two distinct Twitter personas. One is for Dr. Stephen J. Kinzey, featuring a profile picture of the human torso, used to chat with exercise physiology students. The other is for "skinz DDMC So Cal," a private account with a picture of him tearing down the road on his Harley.

Investigators aren't sure what might have tempted Kinzey, if he indeed crossed over from being a weekend rider to being a hard-core outlaw biker.

"He wasn't doing it for the profit. What was he doing it for? To be cool? I don't know. He has a job. He's a tenured professor," said San Bernardino County Deputy Dist. Atty. Steven Sanchez, who heads the gang unit. "That's how a lot of guys move up. I can bring money into the club. I can increase our reputation."

Biker gangs

Kinzey's romance with biker gangs started while he was teaching at the University of Mississippi in 1997, when he joined the local chapter of the Boozefighters Motorcycle Club just as he was getting a divorce, court records show. Its consummation occurred a little more than a decade ago, when he moved to San Bernardino County, birthplace of the Hells Angels and Vagos motorcycle gangs.

Kinzey started two local motorcycle clubs in Southern California, but moved on or was forced out of both, before forming the mountain chapter of the Devils Diciples. It was a band of about six members from the San Bernardino Mountains and neighboring towns.

There were recent signs of trouble. One Diciples member stabbed another biker last November outside of Chad's Place in Big Bear, a popular biker hangout. Three others have been charged with possession of methamphetamine with intent to sell.

Along with Kinzey, local Diciples members declined to comment for this article. But two people familiar with the bikers, who know Kinzey personally, said others in the chapter did not sanction a drug ring.

The Devils Diciples started in Fontana in 1967 but is now headquartered in Detroit, Kinzey's hometown. The club is believed to have about 150 members nationwide, and its website explicitly states that it is a motorcycle enthusiasts' organization and "NOT a criminal organization."

"Diciples" was purposely misspelled to distance the club from any religious affiliation.