In this chilling conclusion to our Working Late series, we're diving into the frightening world of medical professionals who killed again and again.

In our continuing exploration of the most popular jobs for serial killers, we're taking a deep dive into those murderers who spent time in the military. It's a job that literally taught these men to kill, and they wielded that skill with alarming ferocity.

The number of psychopaths who hold positions with "CEO" in the title would alarm you… even if it wouldn't surprise you.

At the halfway point of this Working Late series, we want to look at the people whose work is often overlooked, but that keeps society running.

You pass them every day in the car, truck drivers hauling things from one end of the country to the other. But do you ever think about how that transient lifestyle makes truckers the perfect serial killers?

This is the first episode in our Working Late series, where we'll be taking deep dives into the most popular jobs among serial killers. We'll look into what makes each of these six professions so perfect for killers, and explore stories of the monsters who twisted their day job to suit their darkest after-hours pursuits.

By the end of summer, 2000, Joshua Wade had murdered at least one woman, and possibly many more.

In 1993, a 13-year-old boy was sent to live with his father in Alaska, where he grew into one of the state’s deadliest serial killers.

As an adult, Cary Stayner finally turned his darkest fantasies into reality. Using TV crime shows as textbooks, he killed his victims, then laid out a path of false clues to confuse investigators.

As a troubled teen in the ‘70s, Cary Stayner experienced violent fantasies and compulsions, as well as the traumatic kidnapping of his brother. He found refuge in Yosemite National Park as an adult, but unfortunately, it didn't halt his spiral into murder.

Timothy Joseph McGhee joined the Toonerville Rifa Gang as a boy, and quickly rose through the ranks. By the year 2000, he had turned the low-level Los Angeles gang into a very real threat.

Carl Großmann’s entire life was marked with an obsession with sexual dominance. As a young man, he violated children and animals as a way to emphasize his own power. But when World War I left Berlin in a state of desperation, Großmann found a new, horrific way to satisfy his murderous cravings.

After spending much of his early life as a devoted career criminal, Ed Edwards emerged from prison willing to turn things around.

Beginning with a traumatic childhood is a common origin story among serial killers. But not every child with a troubled upbringing sets out to become a lifelong criminal.

By the summer of 1984, Leonard Lake finished construction on his fallout shelter. There, Lake and his partner-in-crime, Charles Ng, tortured, raped, and murdered countless female victims.

Fearing a nuclear apocalypse was imminent, survivalists Leonard Lake and Charles Ng dreamed of building a bunker in the middle of nowhere.

After he killed his friend Cherie in 1980, Randy Woodfield was a clear suspect in the murder — but he still managed to walk free.

He was a star football player in the early 1970s. A talented athlete with every chance for boundless success. But he developed a nasty temper, and a ferocious sense of entitlement.

After his first three murders, Kenneth McDuff was quickly apprehended and brought to trial.

Kenneth Allen McDuff led a charmed life. He was an angelic child. At least, that's what his doting mother thought.

As a long-haul trucker, Eckert realized his job afforded him the perfect conditions to kill.

From a young age, Volker Eckert displayed a strange fascination with women’s hair. His fetish led him to murder in 1974, when he was just 14 years old.

Some serial killers’ reigns of terror are cut mercifully short, due to careless mistakes or careful police work. Pedro Alonso López was not one of those killers.

John Joseph Joubert was plagued by disturbing daydreams, along with a horrifying urge to hurt little boys, and in the 1980s, he finally acted on both.

Having graduated from brutal assaults to murders, Paul Ogorzow felt untouchable as he rode the rails, throwing his victims off speeding trains.