It is in the clips of his songs with a few thousand views on YouTube that the 21-year-old young man, unemployed after having given up on pursuing higher education, gives a glimpse of the violence that inhabits him.

The protagonist of one of these videos, which are now unavailable, shoots at people, in a cartoon style with rough features, before finding himself lying in a pool of blood, shot by the police .

“I just wanna scream/Fuck the world/I’m living my dream,” Bobby Crimo raps over the footage.

In another song, published eight months ago according to local newspaper Chicago Tribune, he gloomily blurts out, “I just need to do this,” then “It’s my destiny. It’s all led me to this. Nothing can stop me, not even myself.”

– “So full of anger, hatred” –

The mayor of Highland Park, a wealthy city in the north of the United States, said that she knew him when he was a young scout and that she supervised his group.

“He was just a little boy,” Nancy Rotering told NBC, adding, “And you wonder, what happened? How could someone get so mad, so hateful, to go after innocent people who were just having a day out with their family?”

Described by a witness as “methodical”, the killer perched on the roof of a business in Highland Park on Monday to coldly fire a powerful rifle in bursts at the crowd gathered to watch the July 4th parade.

Five people died on the spot, another died in hospital, and dozens of parade spectators suffered gunshot wounds.

Bobby Crimo was arrested “without incident” at the end of the afternoon after a brief chase. He had “disguised himself as a woman” to escape the police.

– Face tattoos –

This frail white man, with long black hair, has his face marked with several tattoos, such as a “47” on the right temple and an “Awake”, his rapper name, above the left eyebrow arch.

His uncle, Paul Crimo, with whom he lives in nearby Highwood, described him as a “very quiet kid”, a “YouTube rapper” who “doesn’t talk, just sits at his computer” and with which he had “no interactions”.

The nature of the relationship between Bobby Crimo and his father Bob, a grocer who had fought an unsuccessful 2019 campaign to become mayor of Highland Park, was not immediately clear on Tuesday.

A friend of his from whom he had recently become estranged, Bennett Brizes, told the Washington Post that Bobby Crimo was “always apolitical”. “I don’t know, man,” he invariably replied when asked his opinion on world affairs.

He had however posted on his now blocked Twitter account a photo showing him with a Trump flag around his shoulders, as well as a modified drawing of “Pepe the frog”, a character who has become a rallying symbol for the American far right.

In another clip he directed, chilling footage shows him alone in a classroom, decked out in a helmet and body armor, with eerie, sardonic laughter playing in the background.

In another video, spotted by the Washington Post, he said “hate when others attract more attention than (him) on the internet”.