Philadelphia- KYW Newsradio has learned that an autopsy has determined that the murdered sex flick star whose body was discovered last week in Whitemarsh had sex at or just before the time of her death.

Investigators now know that Natel King had sex close to the time she was stabbed to death, apparently during a bondage photo session.

Now, according to DA Bruce Castor, they want to find out if it involved her accused killer — photographer Anthony Frederick:

“The medical examiner found semen in the young woman’s body, which we need to compare to known samples from the alleged killer.”

A search warrant has been signed by Judge Benjamin Crahalla that will allow detectives to take blood, hair, and saliva sample from Frederick, who is at the county prison.

Castor notes, however, that while Frederick is the suspected killer, someone else could have been the lover.