A Golden Gate Transit official on Wednesday said a retired employee of the agency who was arrested in Santa Rosa on suspicion of stealing a bus had knowledge of how to start the vehicle using a keyless electronic system.

"The buses are secured. You have to know how to get into them and start them. It's not an intuitive process," said Mary Currie, spokeswoman for the Golden Gate Bridge Highway and Transportation District.

Novato police arrested Richard McAulay, 48, on Tuesday afternoon in Santa Rosa on suspicion of vehicle theft and a variety of drug charges.

Police had been dispatched to Golden Gate Transit in Novato at about 4:15 p.m. for a report of a suspect driving off in a stolen bus, which headed north on Highway 101.

The bus was found in Santa Rosa, where McAulay lives.

Currie said McAulay worked for the transportation district from May 2000 until his retirement in December 2010. She declined to speculate on a motive for the alleged theft.

Police found what they suspect was heroin and drug paraphernalia in McAulay's possession at the time of his arrest.

He was booked into Marin County Jail on suspicion of vehicle theft, possession of narcotics, possession of narcotics paraphernalia and being under the influence of a controlled substance.