LOS ANGELES, CALIFORNIA: John Meehan, who was known as "Dirty John," died in 2016 after one of his victims attacked him in self-defense during a kidnapping attempt.

Meehan was given the moniker when he was in law college. NBC's 'Dateline' will re-explore Meehan's life and crimes. The episode, titled 'The Women & Dirty John', will air on Friday, September 8 at 9 pm ET.

The Real John Meehan behind 'Dirty John'

Meehan had a troubled childhood following his parents' separation.

His upbringing was quite questionable as he was brought up by his father who owned a shady casino and kept scammers and cheaters close, his sister Donna told the 'Simon Says' podcast.

It didn't take long for Meehan to be influenced by his father's nature and learn some of the petty crimes. He eventually went on to deal drugs, for which he would get an active charge in the state of California during the '80s.

Meehan decided to pursue higher studies, which included law school but then eventually turned to nursing school where he obtained his license for anesthesiology.

He was only able to make it through college with the financial support of his lover-turned-wife Tonia Sells.

They ended up getting separated when Sells discovered Meehan's real past including his drug addiction.

For the next few years after 2000, Meehan would come to the attention of police officials for stealing drugs from the hospital he worked at and at one point, according to the LA Times.

This would eventually make him lose his license as an anesthetist. Meehan had to serve 17 months in prison for drug theft.

John Meehan and Debra Newell's strange relationship

Mehaan met Debra Newell through a dating website for middle-aged people. Newell was a successful businesswoman with multiple failed marriages, looking for love.

She has four children from those marriages and the way Newell and Meehan's relationship was progressing did not sit well with the daughters. They had gotten married in Las Vegas within months of knowing each other.

One of Newell's three daughters, Veronica, was especially suspicious of Meehan, and had tried to get her mother to see him for what he was, but it did not work.

Newell's daughters' disapproval of Meehan was obvious and he took to extreme measures to keep them away, proceeding to harass another daughter Jacquelyn.

This was Newell's breaking point and she decided to end things with Meehan after that.

How did Dirty John die?

Newell's daughter, Terra, almost died before she stabbed Meehan to death. She reportedly said, “He was accusing me of wanting to take my mom away from him and also accusing me of snooping through his things.”

She added, “It made me question what is he trying to hide.”

When she was 25, Meehan attacked her in the parking lot of her apartment close to Newport Beach. It was a kidnapping attempt as Terra had recounted being pushed into a car.

She was able to defend herself using the knife which Meehan had held. Terra went on to stab Meehan several times until he was unconscious.

Four days after the parking lot incident, Meehan was declared brain dead in a hospital and was taken off of life support by his sister Karen.