Robert Bierenbaum killing Gail alayne Katz, wife janet challot chollet

Ex-surgeon confesses to murdering his wife and dumping her body from a plane.

According to a report released Thursday, a former plastic surgeon who had long denied killing his wife admitted to strangling her to death and dumping her body out of an airplane.

Robert Bierenbaum, who is serving a 20-year to life sentence in prison, revealed facts of the 1985 murder during a December 2020 parole hearing, the transcript of which ABC News has received. He was convicted in 2000 on circumstantial evidence given at a murder trial in Manhattan, but this is the first time he has admitted to killing Gail Katz.

"I attacked her because I wanted her to stop yelling at me," he reportedly told the parole board during the hearing.

Robert Bierenbaum killing Gail alayne Katz, wife janet challot chollet
Dr. Robert Bierenbaum and his wife Janet take a walk during a break in their murder trial. Bierenbaum, a plastic surgeon, is charged with murder and dumping his prior wife's body into the Atlantic Ocean from an airplane in 1985.

Bierenbaum, now 66, was 29 years old when he murdered his wife, who was also 29.

According to the transcript, Bierenbaum attributed his behavior to being "immature" at the time and not understanding "how to cope with his rage." Additionally, he explained what he did to the body, which was never discovered.

"I took flight. "I opened the door and then escorted her body from the airplane over the ocean," he allegedly stated.

Prosecutors allege that Bierenbaum hired a plane out of New Jersey on the day of his wife's death but fabricated a flight log to make it appear as though he flew the following day. Their marriage was apparently poisonous, with Katz reportedly telling a neighbor that she no longer felt at ease in her own house.

According to ABC News, her sister stated that Bierenbaum spotted his wife smoking on their balcony one night and choked her until she passed out. Katz notified authorities about the attack, but her husband was not charged.

As the case drew to a close, Bierenbaum remarried, had a daughter, and established medical businesses in Las Vegas and North Dakota. However, prosecutors did not abandon the case and charged him with second-degree murder more than a decade after the incident.

According to The New York Times, Katz's sister, Alayne, said in court during Bierenbaum's 2000 sentence hearing that her brother-in-law murdered the victim "to protect her from exposing him as a violent and sick guy."

Dan Bibb, one of the case's prosecutors, told ABC that he was "stunned" by Bierenbaum's confession since he believed the convicted murderer would never "own up" to his conduct.

Bierenbaum remains imprisoned, but the network reports that he will get another chance at release at a November hearing.

ABC's investigation is included in a two-hour special edition of "20/20" scheduled to run Friday night.