HomeABC NationalHighland Park mass shooting: Six killed at parade, police scouring person of interest’s social mediaHighland Park mass shooting: Six killed at parade, police scouring person of interest’s social mediaTue, July 5, 2022 by ABC NewsSHARE NOW Mark Borenstein/Stringer via Getty Images(CHICAGO) — Authorities are combing through social media posts they believe are associated with the 22-year-old person of interest in Monday’s mass shooting at a Fourth of July parade in Highland Park, Illinois.Six people were killed and about 24 others were seriously hurt in the suburban Chicago shooting, which police described as a “random act of violence.”It appears the gunman fired from a roof where a high-powered rifle was recovered, police said.Person of interest Robert “Bobby” Crimo III — who was apprehended Monday evening after an hours-long manhunt — is believed to be linked to social media posts that discuss or depict acts of violence, including shooting people, a law enforcement source briefed on the case told ABC News.Analysts say Crimo appears to have had an extensive online presence that was littered with signs of hatred, mental health issues and a gravitation toward hard-right and neo-fascist ideologies.The mass shooting broke out when Highland Park’s parade was about three-quarters of the way through Monday morning, authorities said. Revelers fled in panic, leaving behind empty strollers, overturned chairs and half-eaten sandwiches.Police ran toward the shots but the gunman had already fled, Lake County Sheriff Deputy Chief Christopher Covelli said at a news conference.When the gunfire erupted, parade-goer Zoe Nicole Pawelczak grabbed her dad and started running through the sea of people.“I saw multiple people slaughtered,” she told ABC News.“Everybody is crying. We ended up making it behind a corner and we hid behind a dumpster. This man was there with his two very young children and he had put them in the dumpster for safety,” she said.Pawelczak said the man wanted to leave to find his other son, and asked her to watch the two children in the dumpster.“So I watched his kids for him,” she said. “They were like, ‘What’s going on?’ And I was like, ‘It’s just fireworks, it’s OK,’ just trying to keep them calm.”Dr. David Baum was watching his grandson, daughter and son-in-law march in the parade when the gunfire began.“Bodies were horribly, horribly, horribly injured from, you know, guns and bullets that were made for war — not for parades,” Baum said of some of the victims.“The paramedics went quickly and assessed the damages — saw bodies that were blown apart and put a blanket over them quickly. And then went on to try and help other people,” he told ABC News. “These are injuries that nobody should have to see.”Five people — all adults — died at the scene and a sixth victim died at a hospital, said Lake County Coroner Jennifer Banek.The NorthShore University Health System said it received a total of 31 patients; most suffered gunshot wounds and a few were hurt in the chaos. At least one child was critically injured, Highland Park Fire Chief Joe Schrage said.Crimo was at large for hours after the shooting. After police released an image of Crimo and his car Monday evening, he was spotted driving and led police on a brief pursuit, authorities said.He was stopped at U.S. Highway 41 and Westleigh Road in Lake Forest, Illinois, where he surrendered, according to police.The neighboring suburb of Evanston canceled its own Fourth of July parade in the wake of the shooting, Evanston police said.President Joe Biden said in a statement that he “surged Federal law enforcement to assist in the urgent search for the shooter.”“Members of the community should follow guidance from leadership on the ground, and I will monitor closely as we learn more about those whose lives have been lost and pray for those who are in the hospital with grievous injuries,” Biden said.He noted that he recently signed into law the most significant gun control legislation in decades, adding, “But there is much more work to do, and I’m not going to give up fighting the epidemic of gun violence.”Vice President Kamala Harris said in a statement, “On what should be a celebratory day with family and friends, we are grieving the lives that were taken in another act of senseless gun violence.”“More should be done to address gun violence in our country,” she said. “President Biden recently signed into law the first major bipartisan gun reform legislation in almost 30 years — and we will continue fighting to end this senseless violence.”In an impassioned statement Illinois Gov. JB Pritzker said, “There are no words for the kind of monster who lives in wait and fires into a crowd of families with children celebrating a holiday with their community. There are no words for the kind of evil that robs our neighbors of their hopes, their dreams, their futures.”“Prayers alone will not put a stop to the terror of rampant gun violence in our country,” the governor wrote. “We must — and we will — end this plague of gun violence.”Representatives of the gun reform group March For Our Lives, founded by survivors of the 2018 high school mass shooting in Parkland, Florida, said in a statement, “Just three weeks ago, young people organized a March For Our Lives in Highland Park, along with communities across the country.”“We are grieving for the horrific loss of life in Highland Park, and the carnage brought on by a high-powered rifle,” they said. “We wish eternal peace for those who were murdered, and we will fight like hell for the living.”New Jersey Gov. Phil Murphy is among the leaders reacting to the nation’s latest mass shooting, tweeting, “Not even a parade on the Fourth of July celebrating our nation’s independence is immune from our nation’s gun violence epidemic. Tomorrow, I will sign seven sweeping commonsense gun safety bills into law. We cannot wait.”Law enforcement has long been concerned about gunmen firing from elevated positions, which police say can give them a strategic advantage.The deadliest example of that is the 2017 Las Vegas massacre, during which the shooter took up a window position in the Mandalay Bay hotel. Fifty-nine people were killed in what became the deadliest mass shooting in modern U.S. history.In the wake of the Vegas massacre, law enforcement around the country placed a greater emphasis on securing elevated locations surrounding public events, but police have acknowledged how daunting a task it is to secure all such positions.This is a developing story. Please check back for updates.ABC News’ Josh Margolin, Pierre Thomas, Alex Perez, Jack Date, Will McDuffie and Caroline Guthrie contributed to this report.Copyright © 2022, ABC Audio. All rights reserved.