Co-workers of Donald Harvey often joked that he was the “Kiss of Death” and “Angel of Death,” having no idea he was actually a serial killer.

People liked Donald Harvey. He was considered an expert at his job, working at several hospitals in Kentucky and Ohio as an orderly and nurse’s aide. There was one funny thing about him, though: A lot of people died on his watch. It got to the point where his co-workers would tease him about it, calling him the “Kiss of Death” and “Angel of Death.”

Harvey even got in on the fun, saying things like, “Well, I took care of another one for you,” according to the news service UPI. But, he wasn’t joking. Donald Harvey was a serial killer, and from 1970 until he was brought to justice in 1987, he murdered 37 victims (though he claimed to have killed many more).

Donald Harvey was born outside Cincinnati in 1952. As an infant, his family moved to Booneville, Kentucky, a small Appalachian town with a population in the 100s, located in one of the state’s poorest counties. His family was poor, and his parents often fought, according to the Daily News. Although he dropped out of school in the ninth grade, he began working as an orderly at Marymount Hospital in London, Kentucky, at age 18.

At Marymount, Harvey committed his first murders. His first victim was 88-year-old Logan Evans, an incontinent stroke victim, whom Harvey smothered with a pillow in May 1970, after the patient smeared feces on him, according to the Daily News. Over the next several months, Harvey claimed, he murdered several elderly patients out of mercy. These did not, however, include Ben Gilbert, 81, whom he killed by puncturing his bladder with a coat hanger that he shoved through a catheter, according to the Times Tribune.

Harvey left Marymount Hospital in 1971, and a few months later, he enlisted in the U.S. Air Force. After nine months, he was discharged when officials learned of a prior burglary arrest, reported the Daily News. The outlet also reported that Harvey flirted with the occult and Neo-Nazi groups.

Harvey took different jobs at different hospitals, including the Veterans Administration Medical Center in Cincinnati, where he worked from 1975 to 1985. There, Harvey claimed, he killed at least 15 patients, reported UPI. Harvey used a variety of methods to kill his victims, including asphyxiation, turning off their respirators, injecting air into their veins, and poisoning them with arsenic, cyanide and rat poison, according to The Washington Post.

Around that time, Harvey began a romantic relationship with a man named Carl Hoeweler. Believing Hoeweler had been cheating on him, Harvey began putting non-lethal amounts of arsenic in his food, just enough to make him too sick to leave their home, according to The Washington Post. Jealousy would lead him to fatally poison Henry Hoeweler, Carl’s father, according to the Washington Post. Harvey would also fatally poison neighbors Helen Metzger and Edward Wilson, reported The Cincinnati Enquirer.

In 1985, security guards at the VA hospital found a loaded .38-caliber revolver, hospital supplies and books on the occult in Harvey’s gym bag, according to UPI. The hospital wasn’t able to discipline him, however, because security had no probable cause to search Harvey. He was allowed to resign from his post as an autopsy assistant, and in February 1986, he began working at Daniel Drake Memorial Hospital in Cincinnati, Ohio, reported the Daily News.

Just a few weeks into his new position, Harvey began killing patients, and over the next year, he murdered dozens. Harvey claimed they were mercy killings, and he was quoted in The New York Times as saying, ''I felt what I was doing was right. I was putting people out of their misery. I hope if I'm ever sick and full of tubes or on a respirator someone will come and end it.''

Former FBI Criminal Profiler John E. Douglas, who interviewed Harvey, rejects this notion.

“[H]e was not a mercy killer because some of the things he did were sadistic to the victims, like sticking a coat hanger up through a catheter into a patient's abdomen,” Douglas told Fox News.

His pretension of mercy was also contradicted by the murders of Henry Hoeweler, Helen Metzger and Edward Wilson, none of whom were ill or dying. It appeared that Harvey liked to kill and knew how to get away with it, later admitting it gave him a sense of power and control.

“Some of those (patients) might have lasted a few more hours or a few more days, but they were all going to die. I know you think I played God, and I did,” he would tell Cincinnati Enquirer reporter David Wells in 1987.

In early March 1987, Harvey used cyanide to murder John Powell, 44, who had been on life support for months following a bad motorcycle crash. He was the second person Harvey killed that day, according to People Magazine. He could have gotten away with it, but during Powell’s autopsy, the forensic pathologist smelled burnt almonds, an indicator of cyanide, and alerted police.

When police interviewed hospital staff, Harvey’s name came up, both because of his mysterious departure from the VA hospital and the disturbing pattern of patients dying on his watch. Harvey volunteered to take a polygraph test after buying a book on how to beat lie detector tests, according to People, but called in sick the day it was scheduled. Police then brought him in for questioning, and Harvey confessed to putting cyanide in Powell’s feeding tube, reported the Daily News. He said he felt sorry for the victim, so he killed him.

As spring turned to summer, Harvey was facing one count of first-degree murder. That all changed after news anchor Pat Minarcin, of Cincinnati ABC-affiliate WCPO, inquired on air if the 35-year-old nurse’s aide was responsible for more deaths at Drake Memorial hospital. Anonymous tips came flooding into the station from nurses and hospital staff, who said they had filed complaints about Harvey’s behavior, but claimed they were ordered by supervisors to “keep quiet,” according to WCPO.

The outlet also reported that former Cincinnati police chief Lawrence Whalen said there was no record of suspicions at the hospital, and the coroner asserted that deaths were not unusually high on Harvey's ward.

Before airing their findings, WCPO reached out to Bill Whalen, Harvey’s court-appointed lawyer. Whalen confronted his client and asked if he had killed anyone else. Harvey said yes. When asked how many people he had killed, Harvey said he could only give an estimate, but thought the victim count could be as high as 70.

“When I heard him say the word ‘estimate,’ I knew I was in trouble,” Whalen told the Cincinnati Enquirer in 2003, according to Cleveland NBC-affiliate WKYC.

In August 1987, Harvey appeared in a courtroom in Hamilton County, OH, and pleaded guilty to 24 counts of murder and was sentenced to three consecutive life terms in prison, according to The Los Angeles Times. The victims’ families, most of whom thought their loved ones had died of natural causes, were shocked to learn of the murders, and some were angry that Harvey had avoided the death penalty, according to The New York Times.

Harvey went to Kentucky that November to plead guilty to nine more counts of murder, and was sentenced to life in prison plus 20 years, according to The New York Times. He would eventually be found guilty of 37 murders, but following his conviction, he admitted killing up to 50, according to NPR. In his interview with Fox News, John E. Douglas said we may never know how many people he killed.

“It could be in the 90s, as they say, because the way he was killing them, an autopsy would not detect the way he killed them,” he said.

While the state would be more merciful to Donald Harvey than he was with his victims, those inside the prison system have their own ideas about justice and how it should be meted out. On March 28, 2017, Harvey was found badly beaten inside his cell in protective custody at the Toledo Correctional Institution, CBS News reported. He would die two days later at the age of 64 from blunt head trauma, with breaks to his skull and brain injuries, according to The Toledo Blade newspaper.

An inmate named James D. Elliott, serving 37 years for numerous burglary offenses, would later write The Toledo Blade and confess to the murder.

“I initially attacked Mr. Harvey with facial punches. After the third or fourth punch, he was knocked unconscious. After which, I stomped his head off the floor seven or eight times with my foot,” Elliott wrote.

The inmate said that the murder was meant to call attention to inadequate prison meals — and because he had grown up in Kentucky near some of the relatives of Harvey's victims.

“[I] figured it would give them some closure and peace of mind,” he wrote.

In May 2019, Elliot was charged with aggravated murder, murder, and felonious assault, and on July 9, he pleaded not guilty, according to The Toledo Blade.