State and federal authorities, using DNA evidence, said at a news conference that they have linked 10 attacks by the so-called "Nor-Cal" rapist in the Central Valley and the Bay Area since 1991.
Officials said that cases such as this, in which serial rapists attack strangers but fantasize they have a relationship with their victims are very rare.
Moreover, the short, pot-bellied white male in his late 30s or early 40s, with brown spiked hair, targets Asian women in their 20s and 30s.
Representatives of law-enforcement agencies in the nine-county Bay Area have told the task force they are reviewing rape cases for even the tiniest similarities. At the same time, dozens of tips are pouring in from the public.
Authorities said the rapist stalks, then attacks women who live alone or with another woman. The victims' ordeals last hours as the suspect brandishes a gun or says he is armed, then blindfolds and duct-tapes them.
He chats with his victims and even apologizes.
Officials have confirmed the rapist has attacked women as far north as Rohnert Park his first known rape and as far south as Vallejo and Martinez, but suspect he has struck in several other Bay Area locations.
In the Central Valley, the rapist has been linked with attacks as far north as Chico and as far south as Sacramento, Davis and Woodland.
Police began to unravel the mystery last month after sexual assaults on two Sacramento women.
"The investigation uncovered significant forensic evidence that ... revealed the suspect wanted in connection with the Sacramento assault is the same individual responsible for sexually assaulting other women in cities across the Bay Area and the Sacramento Valley, spanning a 15-year period," Sacramento Police Sgt. Terrell Marshall said.
But the rapist's DNA is not on file in any database.
Surveillance cameras in one case revealed the rapist was driving a white 2001 to 2003 Toyota 4-Runner with tinted rear windows, a roof rack and moon roof.
In one case, he posed as a trick-or-treater at the door of one victim, then called her 20 days later to apologize.
Contact Steve Geissinger at firstname.lastname@example.org or 916-447-9302.