Mariska Hargitay is an unusual figure in American history. She is a world-famous actor, but her career is linked with just one role. Literally one role. It's a role she has played for nearly thirty years. Many actors describe a desire to be chameleonic, to be lost in one character after another after another. But if Hargitay has that desire, she has suppressed it. It's almost like she is closer to a late-night host--like Johnny Carson--than to a Jodie Foster or a Nicole Kidman. Then. From left field .We get this documentary. "My Mom Jayne" beautifully follows the standard format of a memoir. Mariska has two storylines unfolding at once; there is the present-day Mariska attempting detective work, then there is the story of the past (the Hollywood glamour, the ocelot in the backyard, the car accident). Think of "Wild," with Cheryl Strayed hiking across a portion of America, in one storyline, and also living through a turbulent girlhood, in a second storyline....