Mariska Hargitay’s new documentary, “My Mom Jayne,” reveals heartbreaking new information about the night her mother Jayne Mansfield died. While shooting her directorial debut, the “Law & Order: Special Victims Unit” star learned how she was accidentally left behind at the scene of the car crash which killed her mother and two other people.

HBO is previewing My Mom Jayne, a documentary about Jayne Mansfield, as told through the eyes of her daughter Mariska Hargitay. Hargitay, 61, an actress best known for playing Olivia Benson on Law & Order: SVU,