Her job, which is intended to establish much-needed consistency in the league’s handling of misconduct cases, is at the center of a decidedly alpha-male environment. But Friel, 58, sees it as a twinning of passions, “a perfect fit.”

To begin with, she is a devout Giants fan, a season-ticket holder whose basement in her Brooklyn apartment is, as The Daily Beast once reported, a blue-and-red shrine to the Jints. Among her earliest memories of growing up in New Jersey is watching a Giants game on a black-and-white television and asking her father: “Who are we rooting for, Daddy? The ones in the black uniforms or the ones in the white uniforms?”

Then there is her professional background. In addition to her 28 years with the district attorney’s office — a time memorialized on her office wall by a framed courtroom sketch of her in full prosecution mode — Friel worked for a security company as a vice president for a division specializing in investigating and consulting on sexual misconduct.In taking the position with the N.F.L., Friel said, she saw another opportunity “to do something that really mattered.” But in the curlicue way of fate, she owes her job to Rice.

Outrage and Overhaul

When video surfaced in 2014 of Rice dragging his apparently unconscious fiancée, Janay Palmer, from an Atlantic City casino elevator, N.F.L. Commissioner Roger Goodell suspended him for two games, only to apologize for the light punishment after an outcry. When more video showed Rice punching Palmer in the face and knocking her to the elevator floor, Goodell suspended Rice indefinitely, but the league’s inept handling of the case had already become a full-blown debacle.

The impact of the grainy video on league officials cannot be understated, Friel said, particularly on the teams’ owners. The ugliness and violence became vivid and real.

“When I saw that elevator video for the first time, I gasped,” she said. “And I’m no stranger to that. I think seeing that, visually, was fairly shocking — not fairly shocking, but very shocking — to everybody who saw it.”