The HBO Original project about Jayne Mansfield is directed and produced by Hargitay and features interviews the "Law & Order: SVU" star conducted with her siblings, biological father and stepmother about the mom Hargitay never got the chance to really know.

Hargitay's touching HBO documentary sees the actor trying to understand her mother Jayne Mansfield, who died when Hargitay was 3 years old.

I couldn’t believe that this truth, this bombshell for me, didn’t ever come to light," says the ‘Law & Order: SVU’ star about going public with her biological father’s identity in an HBO documentary on her mother,