The gunman responsible for the deadly mass shooting at a Florida high school left disturbing clues to his plan and had numerous encounters with law enforcement prior to Wednesday’s gun massacre at Marjory Stoneman Douglas High School in Parkland, which killed 17 people.

According to a CNN report, Nikolas Cruz gave disturbing clues to his intentions in social media posts and in conversations with classmates before he was expelled from the high school he would later terrorize.

On Instagram, Cruz reportedly posted images of guns and knives. And in reference to a school shooting in New York last summer, he reportedly wrote, “Man, I can do much better.”

A former acquaintance told CNN that Cruz had a disturbing way of introducing himself.

“Hi, I’m Nick. I’m a school shooter,” he used to say, according to the source.

CNN obtained records that showed police had visited Cruz’s home 39 times over seven years. Cruz lived with his adoptive mother, Lynda Cruz, until her unexpected death this fall following a brief illness. His adoptive father died years earlier.

The records obtained by CNN do not indicate if Nikolas was the reason for the calls to law enforcement. But a former classmate told the news station that Nikolas was a constant menace, terrorizing animals and throwing rocks at cars. And a neighbor said he took a video of the teen in his backyard with a BB gun, wearing only boxer shorts. His wife said she saw him shooting cans and bottles with the BB gun over and over again over the course of two days in October. The neighbor said that Nikolas would sometimes point the gun at their window.

“She got scared. I got scared,” he said.

According to the Sun Sentinel, Cruz was disciplined numerous times by the Broward County Public School district for fighting and other disruptive behavior, and was eventually expelled from Marjory Stoneman Douglas High School, though it is not clear exactly what prompted the expulsion.

Broward Mayor Beam Furr, who was formerly a library at the high school, said that more could have been done to address the obvious red flags.

“Sometimes somebody absolutely slips through,” Furr told the newspaper, “and this is one of those times.”

He also said that Cruz had been receiving mental health treatment but stopped going to his appointments 14 months go.

“He was going and then he wasn’t,” Furr said. “My concern is … if a kid has been a client at a mental health facility for a year, how was he within 1,000 feet of buying a gun?”

[Feature image: Associated Press]