‘SVU’ Star Mariska Hargitay on Her Mother Jayne Mansfield

Mariska Hargitay was at home, and she was sprinting up the stairs, bounding between the corners of her very full life. I had to hustle to keep pace.

She checked in with her oldest son — tall, polite, home from his first year at Princeton — and supervised the setup of an engagement party she was hosting for her goddaughter. Gardeners buzzed about the terraces of her Manhattan penthouse. She apologized, superfluously, for the noise.

Her latest obsession, a family heirloom grand piano that had recently entered her apartment via crane, dominated the living room, with a custom “M” bench, courtesy of her husband, the actor Peter Hermann (“Younger”). “That’s my next thing — I’m going to learn to play soon,” Hargitay vowed.

Another dash and we were on the floor below, a warren of cozy offices, painted in jewel tones, with overstuffed couches and muscular art by Annie Leibovitz. Tucked on a bookshelf were some of Hargitay’s awards. She has earned Emmys for playing Olivia Benson, the beloved “Law & Order: SVU” hardass, and for producing the 2017 documentary “I Am Evidence,” about the backlog of rape kits.

This is where Hargitay had conceived, edited and even shot some of her newest and perhaps most life-altering project, the documentary “My Mom Jayne.” It’s at once an unflinching portrait of her mother, the 1950s star and pinup Jayne Mansfield, who died when Mariska was 3; a homage to her father, the bodybuilder and actor Mickey Hargitay; and an investigation into her own clouded and secretive origins. Directing the film, which will air June 27 on HBO, and proclaiming her story has unlocked something profound for Hargitay, 61.

“I am so clear now about the truth,” she said. “This big haze came off — a veil of fear. And now I just feel so much at peace. It’s like a miracle to me to feel this way. I never thought I could.”