Hours after the suspect’s arrest at Highland Park, more and more details about the suspect are coming to light. Apparently, the 21-year-old wanted to make a name for himself as a rapper. He posted violent videos on social media.

The arrested man, who is said to have fired the fatal shots at a holiday parade in the USA, previously published music videos with scenes of gun violence on the Internet. The social media accounts believed to be linked to the man have since been blocked.

Archived versions appear to have videos of the alleged gunman trying to make a name for himself as a rapper, according to US media. They were published under a pseudonym. A video uploaded about a year ago shows a comic strip in which several scenes of shootings can be seen. At one point, a gunman lies on the ground in a pool of blood, surrounded by police officers with drawn guns.

Another video shows a man with brightly colored hair and several tattoos, including on his face. He can be seen in a room that is supposed to represent a classroom. Towards the end of the video, he poses in front of a blackboard with a protective helmet and a type of combat vest. He holds up a US flag.

Several US media reported on Monday (local time) about the videos after the alleged shooter was caught by the police hours after the crime. Investigators had previously published a mug shot of the suspect on Twitter. Authorities initially gave his age as 22, but an FBI bulletin later said he was 21.

He is said to have killed at least six people during a US Independence Day parade in Highland Park near Chicago, Illinois. About two dozen injured were taken to hospitals, police said.