The uncle of the suspected shooter who opened fire on a July 4th parade said there were "no warning signs" that the young man was about to carry out the attack.

Robert Crimo III, 22, is accused of attacking an Independence Day parade in Highland Park, Illinois, on Monday, killing at least six people and injuring 30 others. His uncle, Paul Crimo, expressed his deep sympathies for the victims and said he was shocked that his nephew is the suspect.

"There were no signs that I saw that would make him do this," Paul Crimo told Fox 32. "If I did see signs, I would've said something."

Paul added that Crimo is "a real quiet kid."

SUSPECT ARRESTED IN ILLINOIS FOURTH OF JULY PARADE SHOOTING THAT KILLED 6 PEOPLE

Highland Park shooting suspect Robert E. Crimo

Robert E. Crimo, 22, has been identified as a person of interest in the July 4th parade attack in Highland Park, Illinois in which at least six people were killed.  (Highland Park Police Department)

"He keeps everything to himself, and he doesn't express himself," he explained. "So he just sits down on his computer. There's no interaction between me and him."

ILLINOIS 4TH OF JULY PARADE SHOOTING LEAVES 6 DEAD, MORE THAN 30 INJURED; SUSPECT ARRESTED

Highland Park Police arrested Crimo Monday afternoon following an hours-long manhunt.

Crimo allegedly carried out the attack from a rooftop overlooking the parade route.

The 22-year-old also had an extensive online rap catalog, where he published a cryptic track in October 2021 that appeared to suggest he was planning a life-defining act beyond his ability to stop.

"Like a sleepwalker, I am unable to stop and think," Crimo rapped in the song. "My actions will be valiant and my thought is unnecessary. I know what I have to do, I know what's in it, not only for me but for everyone else."

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"There is no past or future, just the now," he continued. "It is more abstract than I can ever imagine. I can feel the atmosphere pushing me in. It's unstoppable, like a wave pulling me under, I can't breathe without it."

"I need to leave now, I need to just do it. It is my destiny, everything has led up to this," Crimo said. "Nothing can stop me, not even myself. Is there such thing as free will, or has this been planned out, like a cosmic recipe?"

"It is what I've been waiting for in the back of my head, ready to be awakened, It is what I've been sent here to do, like a sleepwalker," he added in the track.