Jacobus Dirk Hertogs was born on December 16, 1949, in The Hague, Netherlands. Little is known about his family or childhood. However, we do know that he grew up in a time when post-war Netherlands was changing rapidly.

As he grew older, Hertogs moved into adulthood and began to form relationships. He was known to be in a homosexual relationship with Cornelis Stolk, who was the Vice President of the court in The Hague.

Jacobus Dirk Hertogs was a convicted serial killer in the Netherlands. He was connected to the murders of three young girls.

The first victim was Tialda Visser, who was only 12 years old. She went missing on May 11, 1979, after ballet classes. Four days later, her body was found near the Leeghwaterbrug in The Hague. The cause of her death was never determined.

The second victim was Emy den Boer, an 18-year-old. She disappeared on April 3, 1980, while on her way to school. Her body was discovered on April 5 in a forest near Nistelrode. She had been shot in both the stomach and head.

The third victim was Edith Post, who was 11 years old. She went missing on September 29, 1980, while at school. On October 2, her body was found in the dunes of Wassenaar. She had been beaten to death with a branch.

After the murder of Edith Post, police received an anonymous tip. It stated that her murderer had a bite wound and that a bouncer at a nightclub had been bitten. The police arrested Koos Hertogs, who was that bouncer. They searched his house and found blood that matched the DNA of Tialda Visser and Emy den Boer. In his attic, they discovered an insulated room, which was believed to be where he hid and assaulted his victims before killing them.

Hertogs was sentenced to life in prison. Initially, he denied the murders but later confessed in 1989. He said this confession was to earn a more comfortable prison life.

In 2009, journalist Peter R. de Vries conducted a sting operation to investigate whether Hertogs had killed more people. During the operation, Hertogs made significant admissions. He confessed to kidnapping and murdering the three girls and mentioned having an accomplice in the murder of Edith Post. He also talked about several failed plans to commit murder.

In 2012, a book titled "De zaak Koos H." questioned Hertogs's role as a serial killer. The author suggested that the case might involve a cover-up and speculated about connections to influential people like Cornelis Stolk, a judge who had ties to Hertogs.

Jacobus Dirk Hertogs died in prison on July 19, 2015.