A series of attacks near the University of California at Berkeley campus has women all over town on alert.
Police investigators believe a man attacked four women in the last month by coming from behind and grabbing his victim.
"I'm fairly alarmed by this person by the boldness he has to know we're looking for him," Berkeley Police Chief Michael Meehan said. "He has to know we have video and yet the offenses continue. That's someone we are interested in catching."
Berkeley police on Tuesday night provided the city council an update on the investigation.
"We've contacted sexual assault experts eternally and internally evidence has been sent to a lab," Lt. David Frankel said.
Police will not say what the evidence is, but officers are hoping an analysis will lead to an identification of the suspect.
Meanwhile, the Berkeley Police Department is stepping up patrols, going door-to-door near campus to raise awareness and following leads.
"We've contacted several suspects, identified and interviewed them, and tentatively ruled them out," Frankel said.