Police have used DNA to link a man to the 2001 murder of Ashley Ellerin -- who happened to be dating Ashton Kutcher at the time of her death.

The story goes like this: Back in the pre-Demi days, Kutcher told police he went to pick up Ellerin for a post-Grammy party, but she didn't answer the door. He looked through a back window and saw what he thought were red wine stains on the carpet. He eventually left.

Those weren't wine stains and her body was discovered the next day by a friend.

Michael Gargiulo has been in custody since June for attempted murder of another woman. That's when DNA tests were used to link him to several murders, including Ellerin's.