17-year-old Perry High School shooting suspect posted photo on TikTok before shooting

The student identified as the Perry High School shooter posted a photo of himself on TikTok shortly before police say he shot multiple people and then turned the gun on himself.

Dylan Butler, 17, of Perry attended the high school where the shooting happened about 20 minutes before school was scheduled to start Thursday, the first day of school after the winter break. Police said Butler shot six people, including a sixth-grader who died.

Dylan Butler posts on TikTok before shooting

Before the shooting, Butler had posted a selfie on the social media platform of him in a bathroom stall with a blue duffle bag by his feet. The caption read "now we wait."

Live updates:Sixth grade student killed in Perry school shooting; five other victims shot

The TikTok post, which has since been taken down along with Butler's social media accounts, was accompanied by the song "Stray Bullet" by rock group KMFDM. The song infamously was used on the personal website of Eric Harris, one of the shooters of the Columbine High School massacre in 1999.

Butler had more than 250 followers before his account was shut down.

Butler made numerous social media posts "in and around the time of the shooting," Assistant Director of the Iowa Division of Criminal Investigation Mitch Mortvedt said. Investigators are looking into those posts as part of the investigation, he said.

A law enforcement official briefed on the investigation said federal and state investigators were interviewing Butler’s friends and analyzing Butler’s social media profiles, including posts on TikTok and Reddit. Investigators have also found other photos Butler posted posing with firearms, according to the official, who was not authorized to publicly discuss details of the investigation and spoke to AP on condition of anonymity.

Dylan Butler is the son of Jack Butler, the manager of the Perry Municipal Airport and former public works director for the city of Perry. Calls to the suspect's parents, Jack and Erin Butler, were not immediately returned Thursday.

IED found at the school after the shooting

Dylan Butler was found in the school of "what appeared to be the shooter with a self-inflicted gunshot wound,” Mortvedt said. Police found and disposed of an IED found in the school. Butler had a pump action shotgun and a small caliber handgun.

Perry High School's principal, Dan Marburger, is reportedly among the victims of Thursday morning's shooting at the school. Police did not release any victim names.

What should people do if they see posts like this?

Iowa State Patrol Sgt. Alex Dinkla said after an afternoon news conference that if anyone sees disturbing social media posts they should call 911.

"Report it. Let authorities know," Dinkla said. "If you see something, say something. That's always a good lesson I think everybody should always go by. You never know when it might affect or change somebody's life or save somebody's life."

This story will be updated.

The Associated Press contributed to this report. José Mendiola is a reporter at the Des Moines Register. Reach him at jmendiola@dmreg.com.