Ex-girlfriend of NYC surgeon who threw wife out plane says therapist warned her life was in danger

The ex-girlfriend of the New York City surgeon convicted in the 1985 killing of his wife has exclusively revealed that ‘she feared for her life’ while on a boat trip with the doctor, prompting her to visit therapist who told her that her life was in danger as long as she stayed with the man.

In a new interview with ABC’s 20/20, chiropractor Dr. Stephanie Youngblood detailed the chilling encounter she had with her then-boyfriend, plastic surgeon Robert Bierenbaum, who admitted last year that he strangled his then-wife, Gail Katz, to death and threw her body out of a moving airplane.

While investigators initially suspected Bierenbaum in Katz’s death, he was not charged due to insufficient evidence.

Former New York City plastic surgeon Bierenbaum (left) admitted last year that he strangled his then-wife, Gail Katz (right), to death and threw her body out of an airplane back in 1985

The affluential doctor, whom prosecutors deemed a de facto ‘Dr. Jekyll and Mr. Hyde’ during court proceedings and was known to fly into sudden fits of rage by people close to the couple, walked off scot-free after his wife’s disappearance – until his eventual arrest more than a decade later and subsequent conviction in October 2000.

During that span, though, the successful surgeon started dating again and even remarried at one point, finding a string of unsuspecting suitors unaware of the his dark past.

One of these woman was Youngblood, who said that her relationship with the two-faced doctor started off swimmingly, with the couple attending black tie events and taking lots of ski trips.

However, the pink cloud soon dissipated to reveal Bierenbaum’s dangerous temper and alarming tendencies.

Youngblood recounted one explosive incident with the doctor to 20/20, during a meal on what was supposed to be a romantic cruise. 

At the start of the intimate meal, Youngblood, seated across from Bierenbaum, asked a host for a bottle of red wine for the table.

But when the restaurant worker returned with the bottle and proceeded to open it, it sprayed out of the bottle, enraging Bierenbaum, Youngblood revealed.

‘Bob went ballistic,’ she recalled to ABC’s 20/20 in an exclusive interview airing Friday at 9 p.m. ET.

Youngblood (left) dated Bierenbaum (right) nearly a decade after Katz disappeared, and said their romance quickly went downhill after she was exposed to the two-faced doctor’s fits of rage

‘That’s when I saw his laser eyes,’ she said, before adding, ‘they just pierced my soul.’

Youngblood went on to describe the doctor’s fit of rage after the host’s gaffe, which she said fell solely on her.

‘He just raged on me like it was my fault,’ she said of Bierenbaum’s alleged verbal abuse, which was so intense that she ‘feared for her life.’

‘My life was flashing before my eyes,’ she added.

‘That was a tipping point in our relationship.’

Alarmed by the incident, Youngblood then demanded the pair see a therapist in an attempt to salvage their relationship – something Katz had done a decade before, prior to her death.

The couple only had one session, Youngblood revealed.

After the pair’s appointment, the therapist spoke to Youngblood alone, telling her that the couple had clear ‘issues’ – and warned her that her ‘life could be in danger with him [Bierenbaum].’

At that point, Youngblood says she started to build a strategy to leave the toxic relationship – which she eventually did.            

Youngblood detailed a frightening encounter on a boat trip with Bierenbaum that spurred her to seek professional help and eventually leave the plastic surgeon – before he was revealed to be a murderer

Youngblood added that Bierenbaum told her he had been previously married, his wife had disappeared and he didn’t like to talk about the situation.

‘The way he told the story, it was believable,’ Youngblood said. 

‘He goes, ”Listen, this isn’t for public knowledge. I would really appreciate it if you kept this under wraps.”’

Bierenbaum – who was an experienced pilot – admitted during his December 2020 parole hearing that he strangled his wife at the time, Katz, to death and threw her body out of his private airplane because he was ‘immature’ and ‘didn’t understand how to deal with his anger.’

‘I wanted her to stop yelling at me and I attacked her,’ he said. 

‘I went flying. I opened the door and then took her body out of the airplane over the ocean.’ 

Judge Leslie Crocker Snyder, who presided the case, said that ‘one of the most critical moments’ was the prosecution’s video recreation of a small plane pilot pushing a body bag out of the aircraft while still flying the aircraft

The confession came after the doctor vehemently maintained his innocence for more than 30 years. 

Now, less than a year he took responsibility for the crime, those who knew the couple share exclusively on 20/20 how the outwardly charming doctor with a successful career and many hobbies was, in reality, violent and controlling.

‘The Bierenbaum story when you get right down to it is Dr. Jekyll and Mr. Hyde,’ Dan Bibb, a former Manhattan assistant district attorney who prosecuted the Bierenbaum case, said. 

‘Disbeliefs switched to ”Good God, this guy was a psychopath.”’ 

‘Never in a million years you thought you’d be using cold calculated murderer in the same description as Dr. Bierenbaum,’ a man who knew the couple said. 

‘This perfect renaissance man, spoke several languages, a Jewish doctor,’ echoed Gail’s sister, Alayne Katz. 

‘He was tall, dark and handsome – pilot, surgeon, a big catch right, for any young lady,’ said Denise Kastenbaum, a childhood friend of Gail.  

Bibb said that Bierenbaum’s confession prompted a wave of shock among prosecutors, especially since it mirrored what investigators had hypothesized all along. 

‘I was like, ‘Holy s—, are you kidding me?’ he said. 

‘I was stunned because I always thought that that day would never come, that he would own up, take responsibility for having killed his wife.’

However, Alayne claimed her ex-brother-in-law’s admission of guilt meant nothing: ‘This is exactly the same man that I knew 35 years ago. He hasn’t changed … he is incapable of a shred of remorse.’  

She claims she suspected that Bierenbaum had killed Katz the moment she learned her sister was missing.

‘She’s not with me, and she’s not with my parents, and at that moment I know that my sister’s dead,’ Alayne said. 

‘And if she’s not alive there’s only one person who is a likely suspect to murder her, and it’s Bob. There’s no other suspect.’

Bierenbaum (pictured with his second wife, Janet Chloett) said he killed Gail because he was ‘immature’ and ‘didn’t understand how to deal with his anger’

Gail’s sister, Alayne Katz (pictured), said her ex-brother-in-law’s confession means nothing: ‘This is exactly the same man that I knew 35 years ago. He hasn’t changed … he is incapable of a shred of remorse’

Bierenbaum and Gail met in the early 1980s and had what their friends called a ‘magical romance’.

‘One of the first dates he took Gail on was a flight around Manhattan. She was so enamored,’ Denise said.

However, the couple’s relationship quickly turned toxic.

According to Gail’s sister, Bierenbaum began showing his violent tendencies before the two were ever wed, citing an example where he attempted to drown Gail’s cat in the toilet at their Upper East side apartment. 

‘[She said], ‘No, no, no, Alayne… we’re gonna get rid of the cat and then everything’s gonna be fine because he’s gonna believe that I love him,’ Alayne recalled. ‘And I’m like, ‘No. Not really. You really have to get rid of Bob.’  

Alayne said, despite several red flags, Gail went through with the wedding: ‘My sister told me, ‘I’m smart. I’m loving. My love will cure. This is going to work out.”

During the course of their marriage, Gail grew fearful of her reportedly controlling and violent husband, telling neighbors she ‘didn’t feel comfortable at home’. 

In 1983 Gail reported to police that Bierenbaum had choked her into unconsciousness after he caught her smoking on their balcony. However, nothing came of the complaint.

One of the prosecutors on Bierenbaum’s case described it as an instance of ‘Dr. Jekyll and Mr. Hyde’ (Pictured: Bierenbaum and Katz)

The couple’s romance started off magical but quickly turned toxic. Alayne said she was fearful for her sister Gail (pictured) from the very start

‘If this had happened in 2021 … Robert Bierenbaum would have been in handcuffs immediately,’ Bibb told ABC. ‘The fact that this was [1983] … nothing was done about it.’ 

She disappeared on July 7, 1985. Bierenbaum told police the couple had an argument and Gail stormed out. 

Months after Gail’s disappearance, the Manhattan District Attorney’s Office took over the case and called on Detective Andy Rosenzweig to investigate.

Rosenweig’s probe revealed that Bierenbaum had rented a plane from a New Jersey airport on July 7, 1985 but altered his flight logs to indicate he went flying on July 8. 

The detective theorized that Bierenbaum had thrown Gail’s body into the Atlantic Ocean. However, there was not enough evidence to press charges.

Meanwhile, Bierenbaum returned to the dating scene and attended parties in the Hamptons.

In 1989, a torso believed to belong to Gail surfaced on a Staten Island shore. Because DNA forensics had not been invented yet, officials used a chest x-ray to identify the body.  

‘An X-ray technician compared this X-ray with the torso and said, ‘This is Gail,’ Alayne explained. ‘Now … we have a body to bury. We have some closure.’ 

In 1983, Gail (left) reported to police that Bierenbaum (right) had choked her into unconsciousness after he caught her smoking on their balcony. Nothing came of the complaint

Gail (pictured) disappeared on July 7, 1985. Her body has never been found

However, in 1998, as Rosenweig, nearing retirement, remained haunted by Gail’s cold case. He outreached to the Katz family and convinced them to exhume the torso and have it tested with now-invented DNA technology.

The tests determined the torso did not belong to Gail. 

‘That little, little shred of closure that I had has now been ripped away,’ Alayne stated. ‘I looked up at Dan [Bibb] and at Steve [Saracco], and I said, ‘Now, you better get a conviction.’ 

Investigators reopened the case and decided to interview Bierenbaum, who had since remarried and was living in North Dakota with his wife – a Las Vegas gynecologist named Janet Challot – and daughter.

They also spoke with several of his former girlfriends.

One of his exes told police she was with Bierenbaum in New York City when he received a phone call from Port Authority police, saying they thought they found his wife.

He reportedly told police he would call them back and said to his lover: ‘I doubt it’s Gail.’ 

Bierenbaum was convicted of second-degree murder in Gail’s death in October 2000 – 15 years after she disappeared – after the jury deliberated for five and half hours

‘I thought the demonstration with the airplane was extremely effective,’ Crocker said

 With testimony from his former girlfriends and the record that Bierenbaum took a flight on the day Katz disappeared, investigators moved forward with their case.

‘We knew it was going to be the toughest trial that we’d ever had. No forensics, no eye witnesses, entirely circumstantial,’ Bibb said. ‘There was no foregone conclusion to this case, by any stretch of the imagination.’

Bierenbaum was convicted of second-degree murder in Gail’s death in October 2000 – fifteen years after she disappeared – after the jury deliberated for five-and-half-hours.

Judge Leslie Crocker Snyder, who presided the case, said that ‘one of the most critical moments of the case’ was the prosecution’s video recreation of a small plane pilot pushing a body bag out of the aircraft while still flying the plane.

‘I thought the demonstration with the airplane was extremely effective,’ Crocker said.

Bierenbaum was sentenced to 20 years-to-life in prison.  

The former surgeon, however, maintained his innoncene and attempted to get his conviction overturned on several occasions but was unsuccessful. 

After serving 20 years of his sentence, he confessed to murdering Gail. Her body has never been found. 

Bierenbaum remains in prison and is expected in court next month for a parole hearing.