ABC7 has chosen not to show Crimo's social media posts, which have been removed since the mass shooting.
ABC News National Security Contributor John Cohen joined ABC7 to discuss the content.
SEE ALSO | Highland Park parade shooting suspect planned for weeks; gun legally purchased, authorities say
"This individual wasn't crying out for help. He was screaming out for help. He had a fascination with violence," said Cohen, who is also the former Counterterrorism Coordinator and Acting Undersecretary for Intelligence at the Department Of Homeland Security.
The Institute for Strategic Dialogue tracks and analyzes extremist chatter online. The group's read on Crimo, based on his numerous social media posts across nine different platforms, is this:
He was entrenched in a number of toxic digital subcultures, where he had a significant following.
Videos of what appears to be a portion of the Highland Park July 4th parade route were posted by him 10 months before the shooting.
He appears to be fascinated with death, creating videos that portrayed mass shootings and his own demise.
Based on his posts, they believe he had been planning the shooting for some time.
"This individual not only had quite a bit of content that related to violent activity, but he also seemed to be very much into symbology ,which means he incorporated into his online content, a variety of symbols."
RELATED | Highland Park parade shooting: Witnesses describe chaos after 7 killed, 39 injured
Crimo created and posted his own symbol online. It looks similar to one used by a hate group.
"This is something that should have easily been flagged with the algorithms through social media companies. It wasn't flagged and went on for weeks. So right there, it tells me there's an opportunity for improvement. And I would love to see law enforcement working with social media to prevent that these things," said former U.S. Marshals Service Supervisory Inspector Ed Farrell, who also owns Silver Star Protection Group.
Crimo also appears to be an amateur rapper. Some of his songs focus on death and dying. Since the shooting, his online music has been removed.