On July 4, 2022, a mass shooting occurred during an Independence Day parade in Highland Park, Illinois, United States.

Authorities apprehended 21-year-old Robert Eugene Crimo III more than eight hours after the shooting and charged him the next day with seven counts of first-degree murder.

[4] The shooting began at 10:14 a.m. in downtown Highland Park, with the shooter firing a rifle from the rooftop of the Ross Cosmetics building,[5] a local store on the northwest corner of Central Avenue and 2nd Street.

[10] Footage shot by Chicago Sun-Times reporter Lynn Sweet, a spectator at the parade,[5] shows a participating klezmer band on a float continuing to play as gunfire began, and many attendees running while screaming.

[34] After his arrest, Crimo's home in Highwood, a small suburb just north of Highland Park, was raided by FBI agents.

[37][38] The London-based Institute for Strategic Dialogue said it appeared Crimo's extensive online presence contained posts that gravitated toward far-right and neo-fascist ideologies.

[32] A Highland Park rabbi stated that, three months before the shooting, Crimo had entered Central Avenue Synagogue, a Chabad house, during the Passover Seder and was asked to leave.

[32][36][38] Michael Masters, national director and CEO of the Secure Community Network headquartered in Chicago, said, "Nothing overtly we have identified in his social media posts says this was an antisemitic attack, but we are coordinating with law enforcement.

He was in a 4chan bubble of ironic Nazi and anime memes, fascist-inspired music, and mass shooter ideation that basically consumes nothing but irony and sadness.

[51] Stephen Harrison of Slate speculated he had used a single-purpose account on the English Wikipedia in an unsuccessful attempt to create an article about himself in 2017 and 2018.

[54] A voluble supporter of former President Donald Trump, Crimo frequented far-right gatherings, often wearing Where's Waldo garb, and confrontationally joined counterprotests.

When Crimo was two, his mother Denise left him unattended on a hot August day inside a car with windows rolled up.

[58] He was not charged with a crime at the time, but a “clear and present danger report” was filed with the Illinois State Police.

[13] On either occasion, Highland Park police could have invoked Illinois' red flag law, which would have allowed them to seek a restraining order preventing Crimo from buying guns for up to six months.

[60] When asked why the "clear and present danger" report did not prevent Crimo from obtaining a FOID card, Illinois State Police said that Crimo denied that he would harm himself or others when questioned; moreover, "no one, including family, was willing to move forward on a complaint" or to provide pertinent information relating to threats or to mental health, any of which could have enabled further action by law enforcement.

The clip was filmed and posted by a woman who identifies herself as a "registered nurse, mental health advocate, and investigative journalist" on her conspiracy theory blog.

Crimo Jr. described the entire situation as a nightmare, saying the family is shocked at the behavior because he believes his son was raised with good morals.

He lived with his wife, Highland Park native Denise Pesina Crimo, who had a criminal history dating back as far as mid-2002.

[72] The Chicago White Sox announced they would continue to play their baseball game against the Minnesota Twins but canceled their fireworks show.

"This decision was made after careful consideration and in close consultation with many stakeholders, including neighbors, public officials, artists, and patrons.

Our shared hope is that the reduced activity—both within the park and in the neighborhoods surrounding Ravinia—will give the community the space and quiet to reflect and heal.

[78] With the city's blessings, the Highland Park Community Foundation also offered grants to the victims and to nonprofit organizations helping those affected.

[79] On June 20, 2023, Highland Park resident Billy Corgan, owner of the National Wrestling Alliance (NWA), announced that the NWA would run a charity show for the benefit of Cooper Roberts, the youngest person wounded by gunfire, and his twin brother Luke, injured in the ensuing panic.

[84] Crimo's parents released a statement through their attorney, stating: "We are all mothers and fathers, sisters and brothers, and this is a terrible tragedy for many families, the victims, the paradegoers, the community, and our own.

"[53] President Joe Biden stated that he was shocked by the "senseless" gun violence and has offered the "full support of the Federal government" to the affected communities.

Gubernatorial candidate Darren Bailey advocated for "prayer and action to address rampant crime and mental health issues," calling the attack a "horrific tragedy".

[11] Illinois State Senator Julie Morrison and U.S. Representative Brad Schneider were in attendance and expressed their condolences.

Schneider stated he and his campaign team were safe and highlighted his commitment to make the community a safer place.

[94] The websites The Daily Wire and Disclose.tv posted tweets emphasizing the shooter's clothing, which subsequently resulted in transphobic narratives spreading online.