Dr. Henry Bello, the lone gunman who opened fire on doctors and medical students at Bronx’s Lebanon Hospital after hiding a rifle under a white lab coat, was an embittered former employee ousted after sexual harassment allegations.

The ex-employee, angry at what he called “bogus” allegations, had worked in family medicine and threatened to kill co-workers there before he returned to the hospital and made good on that promise. He opened fire with an AM-15 rifle inside the hospital, sending patients, doctors, and nurses scrambling for cover and barricading doors. At least one person, a female doctor named Tracy Tam, has died, and six people were shot overall.

“Gun!” shouted a doctor who spotted the rifle under Bello’s white lab coat, according to The New York Post. Bello bought the weapon on June 20 at Upstate Guns and Ammo in Schenectady, New York, The Daily News reported, adding that the purchase appeared to be legally made because Bello had no felony convictions on his record, despite a series of legal problems.

Two hours before the rampage, Bello wrote an email to The New York Daily News that said, in part, “This hospital terminated my road to a licensure to practice medicine.” He said he was the target of “bogus complaints.” His life story reveals a downward spiral of bankruptcy, divorce, workplace problems, homeless shelters, and arrests.

Other news stories reported the gunman’s name as Henry Bellow, but he’s listed as Dr. Henry Bello on the hospital’s website. NYPD wrote on Twitter that “an assault rifle was found nearby. The subject was wearing a white, medical type coat.”

The mass shooting unfolded at 173rd Street and Grand Concourse in the Mt. Eden section of the Bronx hospital, which is one of New York’s busiest. The carnage might have been even worse, but the injured fell inside a hospital equipped to treat them. “At least one doctor was being treated by people inside the hospital who had tied an emergency fire hose as a tourniquet,” according to The New York Times, which added that “police had described the gunman as a tall, thin man wearing a blue shirt and white lab coat. A police official said he had a long gun.”

“One doctor is dead and several doctors are fighting for their lives right now,” New York Mayor Bill DeBlasio said later.

Police said the 45-year-old Bello committed suicide in the hospital, after setting a fire in a nurse’s station with, according to The Daily Beast, a Gatorade bottle filled with gasoline.

A graphic photo has emerged of Bello lying dead on the hospital floor. You can see it below, but be aware that it’s disturbing.

Here’s what you need to know:

1. Bello Was Previously Arrested for Sexual Abuse After Being Accused of Grabbing a Woman & Trying to Carry Her Away

BREAKING PHOTO: Dr Henry Bello, is seen inside the hospital dead father he shot him self. pic.twitter.com/uVOa0IvIGT — New York City Alerts (@NYCityAlerts) June 30, 2017

There were major warning signs in Bello’s life before the mass shooting, which spanned two floors as Bello opened fire on hospital employees, including other doctors. He had a criminal history that mostly involved attacks against women.

According to Pix11, Dr. Bello had three prior arrests, including one for sexual abuse. The New York Post reported that Bello was arrested in August 2004 in Manhattan “following an incident in which a 23-year-old woman said an assailant grabbed her crotch, held her arms, lifted her up and carried her off, saying, ‘You’re coming with me.'”

Bello was “charged with sex abuse and unlawful imprisonment, sources said. Pix11 reported that Bello pleaded guilty to a misdemeanor in the 2004 case and received community service. According to The New York Times, he’d also filed for bankruptcy in the past.

According to The Daily Beast, Bello also had “an arrest for attempted burglary at 5:10 a.m. on April 23, 2003, when he kicked in the door to an ex-girlfriend’s apartment on Buchanan Place in the Bronx.”

Pix11 reported that Bello, in 2009, was “was charged with unlawful surveillance. At least two women complained he was trying to look up their skirts.”

Bello was also arrested once for fare evasion on the New York subway system, according to The Daily Beast.

#Breaking on @PIX11News: Dr. Henry Bello, alleged #BronxLebanon shooter, had 3 previous arrests, one for sexual abuse. — Mary Murphy (@MurphyPIX) June 30, 2017

Bello’s medical license had expired.

NEW: records show Hospital shooter, Henry Bello's medics license was suspended. @PIX11News pic.twitter.com/46HaEg5YKB — Anthony DiLorenzo (@ADiLorenzoTV) June 30, 2017

New York records list his medical permit as “expired.”

The gunman also had personal troubles, although they were in the far past. In 2002, Bello was listed as a respondent in a California divorce that listed minor children.

According to The New York Daily News, police followed a trail of blood at the scene of the shooting, which is being investigated by police as a workplace violence incident, not terrorism.

The early reports came in for an active shooter at the hospital.

“Due to reports of a shooting incident at Bronx Lebanon Hospital, avoid the area of 1650 Grand Concourse,” NYPD tweeted as the shooting news broke. The ATF tweeted that it was responding to the scene to assist the NYPD. According to a tweet from NBC News, “Officials say the shooter in the Bronx, attempted to start a fire on the 16th floor of the hospital. Sprinklers knocked it down.”

The NYPD later revealed that Bello set himself on fire before committing suicide in the hallway.

One woman posted a photo on Instagram showing her barricaded in a room at the hospital, and others gave similar accounts of the panic inside the building. New York Police Commissioner James O’Neill said the shooting erupted on the 16th floor and the gunman was found deceased on the 17th floor.

According to NBC 4, the shooter was wearing doctor’s attire. He “was dressed in a white doctor’s-type coat,” reported the television station. NYPD later confirmed this detail.

2. The Shooter Was a Family Medical Worker Who Resigned Before Being Terminated & Threatened to Kill a Co-Worker

The shooter’s personal travails had spilled over into the work setting, where he’d recently been forced out of his job at the hospital and left embittered and dangerous. He described his emotions in the email rant to the New York Daily News right before the shooting, saying of his ouster from the hospital: “First, I was told it was because I always kept to myself. Then it was because of an altercation with a nurse.” Then, he said he was accused of threatening an employee.

He wrote that he had emailed a doctor after being fired “congratulating her for my termination after she sent out an email to everybody telling them to file complaints against me so I can be terminated for being rude to her….I only said in the email, it remains to be seen if my life is meaningless or disposable.” In the email, Bello said he had spent $400,000 on his medical career that went to waste because of “bogus complaints.” You can read his full email to The New York Daily News here.

The shooter was described as an “ex-employee,” reported The New York Daily News.

Dione Morales, a patient at the hospital, told CBS 2 that Bello was let go “because I guess they figured he was unstable.”

“He said he was going to do this,” she said to the television station. “It was said that he said he was going to kill people two years ago when he was let go – two years.” CBS also reported that Bello had accused the hospital of racism and discrimination.

According to The New York Post, Bello “was searching for a former co-worker who he had promised to return and kill when he resigned in 2015 — but the employee had the day off.”

The employee was a resident whom Bello called and threatened, “I’m gonna kill you,” reported The Post.

Bello was listed as a family physician on the hospital website. However, despite the fact that Bello is listed as a doctor on the hospital website, The New York Post reported that “there are no state records of a Henry Bello with a medical license.” The New York Daily News reported that he “worked as a licensed pharmacy technician in the family medicine unit.”

A Dr. Henry Bello comes up as a “student in an Organized Health Care Education/Training Program” in the National Provider Identifier Database. The New York Times reported that Bello had “received a limited permit to practice as an international medical graduate” to gain experience but the permit expired in 2016. He previously had a pharmacy technician license in California, according to the newspaper. Bello was supposed to be supervised by another doctor.

Witnesses said the gunman was determined to kill.

“I heard two doctors got shot 20 times, both of them,” said Jasmine Mercado, 24, to The New York Daily News. The New York newspaper reported that at least two of the victims were women.

3. The Shooter Was Living in California & Only Returned to New York Recently

A shooter is dead at Bronx-Lebanon Hospital in New York City, NYPD official tweets. Up to 6 people believed hurt. https://t.co/xOTCDHsCZi pic.twitter.com/3HR1Ey5lQc — CNN Breaking News (@cnnbrk) June 30, 2017

Bello had left the state and was living in California. According to CBS New York, he had only recently returned to New York, and he hadn’t been in that state for about a year. Online records show the killer had lived in California for various stints during his life.

Witnesses described a frightening scene in which the man in the white lab coat – whom some said was wearing all black but others said had on a green or blue shirt – walked through the hospital opening fire.

This is the weapon police say he was carrying:

El rifle AR-15 que utilizó #HenryBello en el tiroteo en el #hospital en el Bronx. Es un fusil de asalto muy letal. https://t.co/V4d2EMVALW pic.twitter.com/xaEpA0CUbT — NY1 Noticias (@NY1noticias) July 1, 2017

According to The Daily Beast, Bello asked for the doctor “who had been the subject of his threatening emails two years before” but was told he was not there.

It soon became clear that police had a mass tragedy on their hands in a country that has seen too many of them lately.

News reporters tweeted that police said at the scene that numerous people had been shot. The New York Post reported that those shot were doctors and that as many as three people were shot. CNN reported that “six people were wounded on the 16th floor, and five of those are in serious condition from gunshot wounds.”

The New York Times reported that those shot were doctors, and their condition was not known. PIX 11 later reported that one of the victims has died.

Active shooter in Bronx Lebanon Hospital. NYPD onscene confirming multiple people shot. @PCALive @NYCEMSwatch @Breaking911 — Howie (@howiekg) June 30, 2017

Patch also confirmed that multiple people were shot. The former doctor “had a rifle concealed inside inside the lab coat he was wearing,” reported PIX 11.

4. Bello Was Educated in the Caribbean & Was Staying in a Homeless Shelter, Where Residents Noted His Fastidious Dressing

UPDATE: Shooter down after incident at Bronx Lebanon Hospital, @CBSNewYork reports; police say at least two wounded https://t.co/apNwXZs5f4 pic.twitter.com/3K1WVjnI2g — CBS News (@CBSNews) June 30, 2017

According to Pix11, Bello was originally from Nigeria. However, the New York Times reported that it’s not clear whether Bello was born in the U.S., but he had a social security number since his teens; he was born as Henry Williams Obotetukudo.

After his ouster from the hospital, his life spiraled down to the point where he was “staying at a Bellevue Men’s shelter,” according to The New York Daily News. He made an impression on other at the shelter, The New York Times reported, because of his “neat dress, which consisted of slacks, button-down shirts and stylish glasses.”

It wasn’t his first stint in a homeless shelter, according to The Times.

It hadn’t always been so dire. According to The New York Times, Bello went to medical school in the Caribbean at Ross University School of Medicine in Dominica, and convinced Lebanon Hospital to take a chance on him as a “house physician.” Some neighbors thought he was courteous and friendly, but a former co-worker told The Associated Press that Bello could be “very aggressive, talking loudly, threatening people.”

Doctors and nurses had barricaded themselves inside the hospital as the gunfire broke out. The Daily News reported that Bello shouted “Why didn’t you help me out when I was getting in trouble?” before opening fire.

In the end, reported The New York Post, six people lay wounded: “three doctors, two med students and one patient — on the 16th floor. He then headed up one flight, where he fatally shot a 33-year-old doctor.”

There were also reports that the suspect had barricaded himself inside the hospital with a rifle. However, police then confirmed that the suspect was down. “A total of 6 additional gunshot victims were removed to the ER of Hospital. 5 of them were seriously injured & 1 was shot in the leg,” the NYPD tweeted.

According to CNN, the suspect had ID on him, and “shot himself on the 16th floor.” The Daily Beast reported that the weapon used was an “Anderson Arms AR-15 assault rifle with a standard magazine.”

“The body of a woman who was shot was found near the body of the shooting suspect,” CNN reported. NYPD confirmed this account, tweeting:

A female victim was found on the 17th floor. She was pronounced dead at the scene. — NYPD NEWS (@NYPDnews) June 30, 2017

“One shooter is deceased at the hospital,” a police spokesman confirmed on Twitter.

“Active shooting in Bronx Lebanon Hospital… Man dressed all in black. Smoke from the 16th floor,” the NYPD Special Operations Division tweeted.

5. Panicked People Posted to Social Media From Inside the Hospital

Dr. Henry Bello has been identified as the gunman by the NYPD at Bronx Lebanon Hospital. pic.twitter.com/wUMJXvbEjt — John doe (@juhhhjgghk) June 30, 2017

Frantic reports were posted to social media.

One person trapped at the hospital posted a video to Instagram in Spanish, saying, “just a guy stuck in a room in the hospital.”

https://www.instagram.com/p/BV-dY3flzhZ/

According to PIX 11, “The 120-year-old hospital claims nearly 1,000 beds spread across multiple units. Its emergency room is among the busiest in New York City,” and it’s located near Yankee Stadium.

“I was in the middle of getting an X-ray when security alerted us to the active shooter situation and locked us in,” patient Felix Puno told the Daily News. “Police are here doing a floor-by-floor sweep.”

Krystal Rivera, 23, a hospital patient, told CNN she heard gunshots.

“I barricaded the door with an IV machine, two chairs and my whole bed,” Rivera said to CNN, which described her as seeing a man wearing “a white lab coat” with a rifle.