Kutcher had invited Ashley Ellerin to attend a Grammy party with him three years ago, but when he went to her house to pick her up, the student didn't answer the door. When the actor peered in the window, he saw what he thought were wine stains on the floor, Entertainment Tonight reported on its Web site.
The next morning, Ellerin's roommate found the woman stabbed to death.
Ellerin's parents are reportedly upset that Kutcher did not immediately contact police when he saw the stains, but Kutcher allegedly told police that, at the time, he thought the stains were wine, not the victim's blood.
Authorities said the three-year-old case is being actively investigated.