"You never know the murderer sitting next to you..."

The truth is, you really never know anyone...no matter how much you think you know them, there is always something that someone, even you, is hiding from the rest of the world.

This is no different for Donald Harvey. For all intents and purposes, and everyone that knew him, he was an intelligent man, ambition driven, and very friendly to those he came in contact with.

Now, while all of us have our secrets, most people aren't hiding a murderous personality.

Let's begin this story at the beginning, going back to 1952; the year he was born. He was born in Butler County, Ohio. It wasn't too much after his birth that his family moved to Booneville, Kentucky, which is a small town located close to the eastern part of the Appalachian Mountains.

By his mother's own account, he was raised in a loving environment with a happy family. "He was always such a good boy," she said.

It was a popular opinion that was shared among many. The principal of his elementary school told a newspaper that he was "a very special child to me." He always had a happy demeanor, was clean with a trim haircut and appeared well taken care of.

He was a cute little kid that was reportedly always smiling. To anyone who knew him, no one picked up on anything amiss.

Harvey was very sociable with adults, though tended to stick to himself, and he was something of a teacher's pet. He didn't have much interest in extracurricular activities.

He was always an avid reader and daydreamer. Though now it makes you wonder, given everything, what exactly the boy was daydreaming about.

He was very intelligent, so while he always did well in school, he never had to put much effort into it. However, he was bored in school. In the most likelihood, he wasn't being challenged enough, which led to him later dropping out.

At this point in his life, he was ambition-less, directionless, with no real goals to work toward. And now he had all the time in the world on his hands.

In need of something to do, he decided to move to Cincinnati, Ohio, where he began working as a factory worker. It wasn't the greatest job in the world, but it was honest work and it helped take up his time. But he really didn't know what he wanted to do with his life.

In the 1970's, he was laid off from his factory job. Around that same time, his mother called him and informed him that his grandfather was sick and requested that he come back home and help take care of him. Having no job, no close relationships, and with nothing holding him in Ohio, Harvey agreed.

It was when he arrived back home that Donald Harvey discovered his path, and the harsh reality of the dying.

When he got into town, he spent a majority of his time with his grandfather at the hospital, but was able to establish himself in town rather quickly. And, rather quickly, established a good relationship with the nuns that ran the hospital.

The nuns saw the care he gave to his grandfather and offered him a job as an orderly, and suddenly found what his true purpose was. He accepted the job, not wanting to go back to factory word and his funds were beginning to run low.

He started working the next day.

The orderly job required Harvey to be alone with patients a good portion of the time. Like he did with his grandfather, he sat at the bedside of dying patients. He changed bedpans, inserted catheters, and gave out medications. Keep in mind that he was not trained in any kind of nursing, as he hadn't even finished high school.

Things went well as he settled in for the first few weeks. Both the patients and the employers took to him easily. And even without that high school diploma, he was very intelligent, and as such, picked up on the skills he needed for his job rather quickly, without needing too much training.

Working in a hospital where people are dying and in pain, takes a certain kind of mental strength that some people just don't have. And while he had seen and sat with his grandfather as he died, it was a whole different ballgame to come face to face, every single day, with the dying and suffering. And now with this new position as a hospital orderly, he was immersed within it.

The mental and emotional toll takes out some of the best. Donald Harvey was not immune to the pressures and stress this job brought along with it.

At some point, something within him changed...or was perhaps released. It's unknown if he was just unable to handle to pressure of watching people die, or if perhaps he liked it a little too much. Whatever the reason, he decided to take on the role of Death herself.

He had finally found his life's purpose.

He would decide who lives or who dies.

And in such, began thinking of himself as the Angel of Death. Now, the first person to fall victim wasn't as dramatic as you might expect.

He'd been working at the hospital now for several months, and during every shift he would go from room to room carrying out his regular orderly duties. As time went on, he became familiar with the people on his rounds.

One such patient was a person in a private room that had suffered a stroke. It was a pretty severe stroke, as it really affected the patient's brain. When he entered the room, Donald found that the man had defecated himself and had smeared the feces along his face.

This really pissed Donald off to no end. His rage became so to the point where he was, apparently, no longer in control of himself. Taking a pillow, he smashed it down over the man's face and held it there until the man eventually stopped moving.

In a matter of moments, he went from trusted hospital orderly, to cold blooded killer.

When the man was dead, and he came back to his senses, Donald knew that he had to come up with some kind of cover story. He cleaned the man, including the feces, before taking a shower to further rid himself of any evidence that might have come off on his person.

After which, he called for the nurses.

His death was ruled as natural causes and later Harvey admitted that no one ever questioned his story on what happened. No one suspected that he had anything to do with it and for the first time, Donald Harvey got away with murder.

As time went on, he began to realize what kind of power he had over the patients, even as an orderly. As the weeks continue to pass, he began to feel this power more and more.

His next victim was an elderly woman. She was someone that Harvey saw routinely on his rounds through the hospital. The woman was being kept alive only by an oxygen tank and Harvey decided that, because of this, she must have been suffering. He turned off the oxygen tank and watched her die.

Like before, he cleaned up any evidence and called for the nurses.

Once again, no one suspected that he had anything to do with it. While committing these various murders, he always felt like and saw himself as an omnipotent being, ending the lives of the people he saw as 'suffering'.

More to the point, he had twice now gotten away with it. This empowered him even more to begin to kill more frequently.

Now, generally speaking, people who commit crimes graduate up from small things, such as petty theft to armed robbery and on up through the criminal ranks until they finally build up enough confidence for murder or some other type of felonious crime. This typically begins in childhood into adulthood.

Harvey, however, skipped the small stuff and went straight to murder. However, there still is a level of evolution in his killings. He started slowly, killing one and waiting...making sure no one suspected anything before he moved on to the next. After the second murder, his ego began to swell. He got away with it twice, he could get away with it again.

He began to kill more and in shorter increments.

A main element of his murders was that he did not, like many murderers, have a particular M.O.

Usually, a killer will go after one demographic, such as a particular gender or race, the age of the victims, similar physical features and they (mostly) use the same method of killing.

Harvey, however, did not stick to the general protocol of your typical killer. He used many methods to kill is victims, changing methods with each kill. Very rarely did he use the same method twice.

He used methods such as suffocation with plastic bags, overdosing victims with morphine, and intentionally caused deadly infections to open wounds.

During the first year of his employment at the hospital, he murdered more than twelve people. One murder in particular was rather over the top in the way of brutality.

Now, while none of the nuns or other staff had no suspicions, the patients began to suspect something was amiss. One man actually directly accused Harvey of attempting to kill him, which led to a rather intense argument. This confrontation became violent and the patient struck Harvey with a bedpan, knocking him unconscious.

When he came-to, decided that he would get his revenge. That night he quietly entered the room, an old, dirty wire hanger in hand.

Harvey inserted the hanger into the catheter, which caused a puncture hole, before removing it. This, in turn, caused a terrible infection that got very bad really quickly.

It was only a few days later that the man died and, once more, Harvey had gotten away with another murder. While his murderous streak and job were in steady condition, his personal life was also taking off as far as recklessness goes.

Remember when I said that usually people grow from petty theft to robbery/burglary etc and then move on to murder? Well, he did the reverse of this.

Once he felt confident enough in his murders, he began to burglarize homes. (Note: there is a difference between robbery and burglary) He was very drunk when he entered the home and when questioned by police, given the smell of alcohol and slurred speech, the police wrote him off as a drunk who had wandered into the wrong house. This was even when, in his drunken ramblings, confessed to the various murders he had committed.

The police did investigate his claims, but found no real evidence to support them.

This is an important detail. Many people assume that because a confession is made, that it's taken at face value. However, that's not how the justice system works.

People lie about committing murders all the time. For attention or some other reasoning like fame.

There has to be evidence to support those claims for the police take any legal action on the person doing the confessing. However, there was plenty of evidence of burglary.

He went to court for this crime and paid a small fine. It was after this that he decided that it was a good time to leave Kentucky and enlisted in the Air Force.

His stint in the military was unremarkable and was later given a general discharge less than a year after enlisting. It was said that his superior officers had gotten a hold of his police record from the burglary, which included his confession (regardless of lack of evidence) to the murders.

After his discharge from the Air Force, Harvey once again found himself without a life's purpose. He fell into a deep depression in 1972. In July of that same year, his depression got to a point where he checked himself into a VA Medical Center in Kentucky, where he spent four weeks before he checked himself out. It was only a matter of weeks before he checked himself back in again.

While there he unsuccessfully attempted suicide, which led him to be put into restraints with a doctor's recommendation for electroshock therapy, for which he was subjected to 21 different times.

Even though he showed little signs of improvement, the doctors decided that he would be suitable to be released back into the world.

By the end of 1972, he found himself working at another hospital as a nurse's aid in Lexington. Six months later he took a second hospital job, among others, over the next two years. However, surprisingly, he did not kill anyone over these two years. The reason for this is rather simplistic. He did not have the same access to patients as he once had.

In 1975, he went back to Cincinnati, Ohio where he found work at the VA hospital during the night shift where he did various things that was needed for him to do.

This is where he picked up on his murderous urges. Over the next ten years, Harvey killed on a regular basis. During these ten years, Harvey killed at least another 15 people.

Growing up, my mother gave me a good piece of advice: Never write down anything that you don't want someone else to eventually read/know about. This was not a piece of advice that Donald Harvey's mother gave him.

I say this because he wasn't intelligent enough to NOT write down details of (most of) his murders in detailed journals, which is how there is such an accurate account of what he did to his victims in his home.

So let's go down the list here.

Included in the details of how he killed each victim, there was a listed name.

Like was aforementioned, the way he killed varied.

One patient he suffocated with a wet towel with the aid of a plastic bag wrapped around their face.

He put rat poison in another's food.

With more than one patient, he laced their orange juice with both arsenic and cyanide.

He injected cyanide into a patient's IV.

He injected cyanide directly into the patient's buttocks.

To be the best at his murderous ways, he began studying medical books to learn the best ways that he could conceal what he was doing. Over many years he was stealing small bits of cyanide from the hospital every now and then.

He was able to gain over 30 pounds of cyanide at his home.

The violence that he exhibited was not limited to the hospital. In the early part of the 1980's, Donald was working at the hospital, met a man named Carl Hoeweler, with whom he began a relationship. Harvey moved in with Carl not long after meeting.

At some point during their relationship, Donald began to suspect that Carl was having an affair with another man. As a result of this suspicion, he began to put arsenic into his food.

He did not put in enough to kill Carl, but just enough to make him sick, leaving him unable to leave the house. Harvey took care of him during this time.

At one point he got into an argument with one of his neighbors and his way of extracting revenge on her was to put a hepatitis serum into one of her drinks.

She nearly died as a result before the doctors could properly diagnose and treat the infection.

Although another neighbor, Helen Metzger, suffered a worse fate. He put arsenic into one of her pies. One week later, she was dead.

In 1983, there was an argument between Harvey and Carl's parents, and as a result, started to poison their food as well. Several weeks later, Carl's father had a stroke, at which point he was taken to the hospital.

When Donald visited him, he once again put arsenic into his food. He died later that night. Over the next twelve months, he continued to poison Carl's mother, but he did not end up killing her.

In 1984, Carl and Donald Harvey broke up.

Donald was so enraged over the breakup that he spent another two years trying to poison Carl with a lethal dose. And while he made him sick enough that he had to be admitted into the hospital, he did not succeed in killing him.

He also attempted to kill one of Carl's female friends.

In 1985, as he was leaving the hospital, a couple of guards noticed that he was acting shady and on a split second decision, they decided to search his bags.

Inside they found a treasure trove of paraphernalia which included a .38 pistol, hypodermic needles, surgical scissors, gloves, a spoon that was used for cooking cocaine, several medical books, two books on the occult, and a biography on serial killer Charles Sobhraj.

He was fined $50 for carrying the .38 on federal property and the hospital allowed him to resign (quietly). Because he accepted this offer from the hospital, there was nothing noted on his employment record.

There was never an investigation on whether or not he committed any crimes while employed there and, once more, he got away with murder.

Seven months later, he applied for another hospital job for a part-time position. He did so well, that they moved him up to full-time. It was less than a year later that he was killing again.

He was far too confident at this point, and with the access he had with the full-time position, the rate at which he committed his murders vastly increased.

In just over a year, he had killed another 23 patients, his methodology as subtle as ever.

He shut off ventilators, injected air into IV's (which if you didn't know creates an air pocket in the heart and is an extremely painful death), suffocation, as well as poisoning with arsenic, cyanide, and other types of poison.

It's very rare that a man will kill using poison. Typically, poisoning is something a woman does for several and various reasoning.

But eventually, no matter how lucky someone might think they are, they'll get caught eventually...Harvey's luck started to run out when he met a patient by the name of John Powell in 1987.

Powell was in a coma but had begun a slow recovery. And despite the the fact that he getting better, Powell was found one April morning dead. It was during the autopsy that an assistant M.E. noticed a strange smell.

Now in case you didn't know, cyanide has a smell (that only some people can detect). Bitter almonds is the tell-tale sign of cyanide. With this new discovery, they checked for evidence of cyanide poisoning.

Suddenly this became a murder investigation. The first suspects in a murder case is always those closest to the victim. Spouse, parents, close friends and other close family members. Once they're clear of any suspicion, they move on to other people that had been in close contact with the victim.

The investigators could not immediately find anyone that would have wanted to kill John Powell that was close to him, so they moved on and widened their search efforts for his killer, which included the hospital staff.

They had a few names on a short list and Donald Harvey was among those few and soon enough he was the sole person being investigated. By the time April of 1987 fell upon them, the police had a warrant to search Harvey's residence.

They almost couldn't believe what they found.

They turned up all his poisons, books on poison, the occult, and the best evidence of all...his journals that detailed his murders, including John Powell.

These writing were just as good, if not better than an actual confession. Harvey was immediately placed under arrest. As they investigated further, they found even more torrid details about his life. While initially booked on one count of murder, that number was to soon climb.

Harvey knew he was fucked at this point and decided to take a plea deal, which is often a bargain for a lower sentence.

In August 1987, Donald Harvey confessed to killing 33 people over a 17 year period, however the actual number of victims was more than 70. In court, he confessed to 25 murders and was sentenced to four consecutive life sentences.

As the news broke, other states, such as Kentucky, began doing their own investigations into Harvey. As a result of these other investigations, he received multiple life sentences from more than one state.

By his own admission, Harvey said in an interview that he felt like he had the right to end people's lives when he was asked why he killed. "After I didn't get caught for the first 15, I thought it was my right. I appointed myself judge, prosecutor, and jury. So, I played God."

In March of 2017, Donald Harvey died in prison.

In the way of body count, Donald Harvey is ranked one of the worst serial killers in American history.