Why was Henry Horton IV arrested? Police find handwritten threats in 19-year-old's car in South Florida

On September 18, Henry Horton IV was pulled over by the cops for a simple case of a broken headlight. However, things took a turn for the disturbing when cops, while searching his car uncovered handwritten notes of gruesome detail. On Thursday, October 5, the 22nd birthday wish of the disturbed Florida man landed him in jail.

In these notes, the 19-year-old expressed chilling intentions, including a desire to carry out a shooting spree at his former high school on his 22nd birthday, as well as other murderous plans, such as harming his stepmother. It's important to note that this individual had a history of mental health issues and had previously voluntarily admitted himself to a mental hospital.

Henry Horton (Image via X/@K12ssdb)

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Henry Horton's stepmother defends stepson, despite death threat

A routine traffic stop by Palm Beach Sheriff's County officers in September turned out to be much more than what was expected. Henry Horton IV was stopped near Jupiter, Florida for a broken tail light on his white Jupiter pickup truck. However, once officers searched his car, for which the man himself gave consent, they discovered multiple handwritten notes.

According to a probable cause affidavit obtained by CNN, the handwritten notes inside the vehicle revealed Henry Horton's plans to purchase guns and go on a shooting spree at his former high school, Okeechobee High School in Florida, from where he had graduated in May of last year.

The affidavit detailed that Horton told the officers about his previous mental issues and that he had "thoughts about mass homicide" and wanted to complete them once he turned 22 on January 2, 2026. The plan detailed the murder of 15 people in the school, including the administrator. Henry was living in Okeechobee with his mother, while working as a pizza delivery man, at the time of arrest.

However, this was not it. He told investigators that he scoped out Marjory Stoneman Douglas High School, the very same school where a tragic school shooting took the lives of 17 students in 2018. When he was asked where he was going before being stopped, he replied that he was off to a church in Miami where he had also planned to kill 10 people after his planned 2026 school shooting.

Further investigation by authorities, via his phone, and discord account revealed more killing plans in multiple states, schemes to kill his stepmother, and notes on the components required for making a bomb. According to WPBF 25 News, police also recovered a 9mm handgun, which he had stolen from his mother, along with multiple fillet knives and a burnt glass water pipe.

Henry Horton's mother, Marcie Horton, who called him a "good kid" told WPBF 25 News that Henry had admitted himself to a mental hospital, earlier this year when he was living in Virginia with his father and stepmother. She said that all the hospital did was simply "pump him full of medicine" and had no diagnosis for him even after two weeks.

Henry Horton planned to go on a high school shooting spree (Image via Facebook)

Henry's stepmom Alisha told the outlet that she never felt unsafe with Henry and agreed with his mother in saying that the man needed help and was not a threat to society. She also criticized "the system" for releasing him from the hospital into society, even though he admitted that he was not ready. She even pleaded with the prosecutor's office to not issue a no-contact order. She told the outlet:

"He (Henry) would never. He is having these thoughts and saying these things, but it is because there is more to what is going on with Henry."

She added:

"All they are doing is making him a criminal when he needs help. He needs help to figure out what is going on mentally."

Henry Horton was subjected to the Baker Act, and transported to a hospital for mental health evaluation before being arrested on October 5. He was arrested for Intimidation-written or electronic threat to kill or bodily harm another person. His bond was set at $ 1 million and his scheduled court date is for November 6.