A sexual spark could be driving an arsonist setting car fires in the East Bay.
Over the past month, more than 20 vehicles have been torched in Contra Costa County. Then, on Thursday morning, San Francisco firefighters found two cars that had been set on fire overnight at Sixth and Jessie streets.
Police say arson often mirrors sex crimes, with flames possibly setting off an arsonist's libido.
"It's a sense of euphoria they feel," Richmond Police Detective Steve Harris said, "a sense of excitement that leads to a plateau phase of euphoria when they're able to regain control, set these things in motion and sit back and watch what happens."
Police say that much like sex offenders, convicted arsonists are required to register with the state because they tend to strike repeatedly.
Investigators say they will be contacting registered arsonists in the area of the recent string of car fires. They fear it is a matter of time before there is a confrontation and someone gets hurt.