LOS ANGELES?Hair, blood and semen gathered in as many as 6,000 unsolved rape and murder cases in Los Angeles County are missing and presumably destroyed, according to a county forensic specialist.

“Every one of these cases we can’t solve now means a violent perpetrator remains on the street,” said Lisa Kahn, the deputy district attorney in charge of the forensic science section.

The missing evidence involves cases investigated by the Los Angeles Police Department and the Los Angeles County Sheriff’s Department.

She said that the evidence was apparently destroyed but that she is still trying to find out exactly who did it and why.

The cases were not under active investigation, but the statute of limitations for many of the rape cases had not yet run out.

Detective Rick Jackson of the police department said evidence sometimes is destroyed because of limited storage space.