The suspect, identified as Robert “Bobby” Crimo III, 22, remained at large hours later while authorities searched the area.
Highland Park Police Chief Lou Jogmen said Monday afternoon that police have identified Crimo as an interesting person and warned that he should be considered armed and dangerous.
Police declined to answer questions about how they identified Crimo.
Authorities described his car as a silver Honda Fit with an Illinois license plate DM 80653.
Highland Park Police Chief Chris O’Neill, the incident commander at the scene, urged people to take shelter while authorities search for the suspect.
He said a “very active arrest attempt” was underway.
The July 4 shooting was just the latest to shatter the rituals of American life.
Schools, churches, grocery stores and now community parades have all become killing zones in recent months.
This time, the bloodshed came as the nation tried to find a reason to celebrate its founding and the ties that still hold it together.
Mayor Nancy Rotering said the violence has “shaken us to the bone”, adding: “On a day when we gathered to celebrate community and freedom, we instead mourn the tragic loss of life and struggle with the terror that has been brought upon us.”
The shooting occurred at a spot on the parade route where many residents had set out prime vantage points early in the day for the annual celebration.
Dozens of bullets fired caused hundreds of parade-goers – some visibly bloodied – to flee.
They left a trail of abandoned items that suddenly showed daily life violently disrupted: a half-eaten bag of chips; a box of chocolate chip cookies spilled on the grass; a Chicago Cubs cap for kids.
“There is no safe place,” said Barbara Harte, 73-year-old Highland Park resident who had stayed away from the parade for fear of a mass shooting but later ventured out of her home.
Lake County Major Crime Task Force spokesman Christopher Covelli said at a news conference that “several of the deceased victims” died at the scene and one was taken to a hospital and died there.
Police have not released details about the casualties or injuries.
Lake County coroner Jennifer Banek said the five people killed during the parade were adults and she has no information about the sixth victim, who was taken to a hospital and died there.
Roberto Velasco, Mexico’s director for North American affairs, said on Twitter Monday that a Mexican was killed in Highland Park and added that two other Mexicans were injured.
dr. Brigham Temple, medical director of emergency preparedness at NorthShore University Health Center, said Highland Park hospital received 26 patients after the attack and all but one had gunshot wounds.
Their ages ranged from eight to 85, and Temple estimated that four or five patients were children.
He said 19 of them were treated and discharged.
Others were transferred to other hospitals, while two patients, in stable condition, remained at Highland Park Hospital.
The gunman opened fire around 10:15 a.m., when the parade was about three-quarters through, authorities said.
Covelli said the gunman apparently used a “powerful rifle” to fire from a spot atop a commercial building where he was “very hard to see”.
He said the gun was recovered at the scene.
Police also found a ladder attached to the building.
“Very random, very intentional and a very sad day,” Covelli said.
President Joe Biden said Monday that he and First Lady Jill Biden were “appalled at the senseless gun violence that has brought new grief to an American community on this Independence Day.”
He said he had “called federal police to assist in the urgent search for the gunman, who is currently at large”.
Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives conducted an urgent track of the rifle, agency spokesman April Langwell said.
Federal agents conduct such traces to identify when, where and to whom the weapon was last sold.
Biden signed the most comprehensive gun violence bill passed by Congress in decades, a compromise that showed both progress on a long-standing problem and the deep-seated partisan divisions that persist.
Police believe there was only one gunman, but warned he should still be considered armed and dangerous.
Several nearby towns canceled events, including parades and fireworks, with some noting that the Highland Park shooter was still at large. Evanston, Deerfield, Skokie, Waukegan and Glencoe have canceled events.
The Chicago White Sox also announced on Twitter that a planned fireworks display after the game has been canceled due to the shooting.
“You have here today a tragic mass act of violence that was random at a community event where people gathered to celebrate, and the perpetrator has not been apprehended so far,” said Covelli, the spokesman for the crime task force.
“So, could this happen again? We don’t know what his intentions are at this point, so we’re definitely not sure.”
More than 100 law enforcement officers were called or dispatched to the parade scene to locate the suspected gunman.
Hours after the shooting, law enforcement officers searched an office building near where the shooting took place.
Nearby, armed FBI agents in camouflage had escorted a family of two little girls down Central Avenue.
The children looked visibly scared, even as their mother tried to reassure them that the officers leading and flanking them would protect them.
“Don’t worry, you’re safe now,” she told them.
“These guys will protect you.”
Ominous signs of a joyous event suddenly turned to horror on both sides of Central Avenue where the shooting took place.
Dozens of prams – some with American flags, abandoned children’s bicycles and a helmet full of images of Cinderella were left behind.
Blankets, lawn chairs, coffee and water bottles were knocked over as people fled.
Highland Park is a close-knit community of approximately 30,000 people on the shores of Lake Michigan just north of Chicago, with mansions and sprawling lakefront estates that have long attracted the rich and sometimes famous, including NBA legend Michael Jordan, who in the city for years when he played for the Chicago Bulls.
John Hughes filmed parts of several movies in the city, including: Ferris Bueller’s Day Off† Sixteen candles and weird science†
Illinois Governor JB Pritzker said in a statement, “There are no words for the kind of monster that lurks and fires on a crowd of families with children taking a vacation with their community.”
Gina Troiani and her son were standing in line at his nursery, ready to walk out onto the parade route when she heard a loud noise she thought were fireworks — until she heard people yelling over a gunman. In a video that Troiani shot with her phone, some children are visibly startled by the loud noise, and they scramble to the side of the road as a siren blares nearby.
“We just start running in the opposite direction,” she told The Associated Press.
Her five-year-old son rode his bicycle decorated with red and blue curled ribbons. He and other children in the group were holding small American flags.
The city said on its website that the festivities would include a children’s bicycle and an animal parade.
Troiani said she pushed her son’s bike and ran around the neighborhood to get back to their car.
“It was just kind of chaos,” she said.
“There were people who were separated from their families looking for them. Others just dropped their cars, grabbed their children and started running.”
Debbie Glickman, a Highland Park resident, said she was sitting on a float with colleagues and the group was getting ready to head out onto the main trail when she saw people running from the area.
“People started saying, ‘There’s a shooter, there’s a shooter, there’s a shooter,'” Glickman told the AP.
“So we just ran away. We just ran. It’s like mass chaos down there.’
She heard no sounds and saw no one who appeared to be injured.
“I’m so shocked,” she said.