An attorney at one of the city’s most prestigious law firms – who had a secret passion for S&M – was shot to death by a rival for the affections of a brilliant Ivy League stunner who moonlights as a dominatrix, police sources said yesterday.

After fatally shooting Anthony Ottaviano, musclebound madman David Krieg kidnapped the white-shoe lawyer’s girlfriend, Edythe Maa, a Long Island native who goes by the name Jade Vixen in fetish circles.

Krieg, 42, who was obsessed with Maa, held cops at bay for nine hours before shooting himself in the head with the same gun he used to kill Ottaviano.

“It’s a terrible tragedy,” said Jack Baughman, a partner at Paul, Weiss, Rifkind, Wharton & Garrison, where Ottaviano worked.

“He was a really nice guy. He was a hard worker. He was conscientious. He was careful.”

Ottaviano and Maa partied together at kinky New York City fetish parties, sometimes with him wearing lipstick, a garter belt, stockings and high heels.

His secret leather-loving lifestyle – seen on photos posted on fetish Web sites – turned out to be his downfall.

The violence began when Ottaviano, 40, and his girlfriend returned to her Philadelphia home after a cozy dinner, police sources said.

Krieg, a former client of Maa’s who had been stalking her for months, was waiting for them in a parking lot near her home, police said.

The tattooed lunatic shot Ottaviano and then forced Maa into his car.

Krieg drove around with the petite dominatrix – who specializes in tickle torture, nipple play and “sissy slut training” – for hours.

Maa, who dropped out of a Ph.D. engineering program at the University of Pennsylvania, convinced him to let her go, and he dropped her off at his relatives’ house in West Chester, Pa., shortly after 4 a.m. on Monday, police said.

She immediately called cops, who began a search for Krieg’s car.

Investigators found him quickly and forced him to pull over in a restaurant parking lot.

As Krieg held the gun to his head, cops tried unsuccessfully to talk him out of killing himself.

Hours earlier, Krieg’s panicked parents had called cops, saying they believed he was going to commit suicide, said West Chester Police Chief Scott Bohn.

At that time, police searched his house and found his gun missing – and no sign of Krieg, an avid bodybuilder who has an ex-wife and a child.

Friends of Ottaviano were stunned by the loss of the fun-loving lawyer.

“It’s a dark day. We lost a good person,” Donn Winn, a lifelong friend, told the Philadelphia Inquirer. Winn, who works as a New York state trooper, told the paper his pal grew up in Tonawanda, near Buffalo. Winn said Ottaviano told him two weeks ago that Krieg was stalking Maa.

Ottaviano encouraged her to get a restraining order, but she never did, Winn said.

He added that Ottaviano was close to his father and brother, and still kept in close contact with a large group of pals from their hometown, going back to grade school.

A spokeswoman for the victim’s firm said that he went to New York Law School, where he served on the law review, and graduated in 1997.

Two years ago, he lost his mother to cancer.

“He drove up to Buffalo every weekend for two years to be with her,” Winn said. “That’s the kind of person he was.”

Quite a different person from Krieg, it appears.

Krieg’s expletive-filled MySpace page is filled with kinky photos of the beefy freak being dominated by a slew of sexy bondage gals – including one in which he is on his knees straddled by a riding-crop-wielding woman he called Isabella.

On his last login, he listed his mood as “devious” and wrote, “David is pissed off!”

And his fixation on Jade Vixen – Maa – is well documented.

“Jade Vixen – she’s the greatest fetish model since Betty Page,” he gushed in a MySpace video.

“Jade’s real name is Edythe Maa, from Long Island New York (still has family there),” he wrote in another online rant, giving a cellphone number and her address.

His corseted crush, Maa, appears to have quite a devoted following.

“Umm have I told you that I’d die to work with you?” one fetish photog cooed on her Web site.

Maa boasts that she possesses “an extensive wardrobe of fetish apparel – leather, latex, custom corsets, extreme high heels.”

The SUNY Stony Brook alum – who has a bachelor’s in chemistry – said she loves posing in clothes, and has a 5-foot-4 frame with incredible 32D-22-32 measurements.

Her clients include men, women and transgender folk, she wrote.

But even though she’s OK with a laundry list of kinky activities – like forced feminization, medical play and genital torture – she does balk at some activities. Things like age play, nudity, face-sitting, “intimate activity of any sort” and anything that hurts animals are strictly off limits.

When reached at his Long Island home, Maa’s father said that she was doing well.

“She’s OK, but she’s not home,” he said. He said that she was not in a hospital.

When asked what his daughter did for a living, he said, “Sorry,” and shut the door.

A neighbor of Maa said, “I knew she went to a lot of fetish parties. I’ve seen him [Krieg] come in all the time.”

The neighbor, Cara Diamond, said Maa had lived with her sister. But two months ago, Diamond saw Krieg help the sister move out.

“They’re both really, really smart,” Diamond said of Maa and her sister. “They’re like geniuses.”

Additional reporting by Rebecca Rosenberg and Kyle Murphy

jamie.schram@nypost.com