At Least 6 Dead After Gunman Opens Fire at July 4 Parade in Highland Park, Illinois

At least 24 people have been injured and six are dead after a shooter opened fire at a July 4th parade in the central business district of Highland Park, a suburb in Illinois.

Hundreds of people were forced to run for their lives when gunfire erupted, leaving behind chairs, blankets, and even baby strollers.

The gunman, police said, took aim at them from a nearby rooftop, which they believe he was able to access through an unsecured ladder. They believe the suspect acted alone.

A firearm, a high-powered rifle, was secured at the scene, authorities added.

In a press conference Monday evening, officials said that Robert E. Crimo, III — the 22-year-old identified earlier in the day as a "person of interest" in the investigation — had been taken into police custody near Lake Forest after being stopped by a North Chicago officer who attempted to initiate a traffic spot.

For more on this story, listen below to our daily podcast PEOPLE Every Day.

Crimo, who goes by "Bobby," engaged the officer in a brief pursuit, officials said, but was ultimately taken into custody without incident.

Police said in their evening news conference that they are still considering Crimo a "person of interest," though Lake County Major Crime Task Force spokesperson Christopher Covelli later said, "calling somebody a suspect or person of interest, it's really synonymous."

"This individual is believed to have been responsible for what happened and the investigation will continue," Covelli said. "Charges have not been approved yet at this time and we are a long way from that."

Lou Jogmen, chief of police for Highland Park, had previously described Crimo as being "armed and dangerous." Commander Chris O'Neil has asked residents to shelter in place and remain away from. the scene, which is still actively being investigated.

Covelli said in a press briefing around 2 p.m. local time that the shooting began at 10:14 a.m., less than 15 minutes after the parade was scheduled to begin. The parade was approximately three-fourths of the way through at the time, he said.

Five people died on the scene, while another died after being transported to the hospital, Lake County Coroner Jennifer Banek said in a following press conference at 3:25 p.m. Those deceased on the scene were adults, Banek said, while authorities said at least one person taken to the hospital with critical injuries was a child.

No ages or names of the deceased were given, but Banek said they've been identified and officials are working on contacting their families.

Anyone, including spectators and business owners, who might have video surveillance of the area before, after or during the shooting are being asked to turn their footage into police. The FBI is collecting information as well via 1-800-CALL-FBI or on their official website.

In addition, the Highland Park Police Department have set up a re-unification program at their main office.

Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

The City of Highland Park posted about the incident on their Facebook page shortly after initial reports broke. "Police are responding to an incident in downtown Highland Park," the city wrote. "All 4th of July events have been canceled. Please avoid downtown Highland Park. Take shelter if in downtown HP. More information will be shared as it becomes available."

Police and firetrucks were on the scene for the parade, the city said. Additional emergency crews from all over Lake County responded to the scene with at least 10 ambulances requested. People are being told to avoid the city's downtown area.

Immediately following the shooting in Highland Park, the Glenview, Illinois police announced the cancellation of their July 4 celebrations on Twitter. Glenview is approximately 10 minutes away from Highland Park by car.

"Due to local events and out of an abundance of caution, the Glenview Fourth of July Parade has been canceled," the said. "There have been no incidents or direct threats to Glenview. Glenview Police are now working to clear the parade area. The fireworks show is still going on this evening."

Other towns in surrounding areas have done the same, like Evanston, Illinois, which also canceled their parade. They closed their beaches, too.

Witnesses at the parade describe the confusion and chaos following the shooting.

"At first I heard a pop, and I thought maybe it was a backfire from one of the vehicles that had passed already, or a firecracker," parade-goer Miles Zaremski told CNN. "And then there were multiple pops — and having been in the service a long time ago, it was not a handgun or a rifle, it was more an AR-15 or whatever. I'd say I hear maybe, I'm guessing, about 30 pops. And there was a pause between the first set of pops and the second set of pops. And then the crowd started rushing and stampeding. ... It was just chaotic."

"I saw blood on the sidewalk, I saw bodies that looked to be deceased. I even saw a young boy being coddled by his parents. It was sickening," Zaremski added.

Covelli told reporters in a press conference that many attendees heroically jumped into action to help those injured. Those stories will be shared in the following days, he said.

"Our community was terrorized in an act of violence that has shaken us to our core," Highland Park Mayor Nancy Rotering said in a statement. "On a day that we came together to celebrate community and freedom, we're instead mourning the tragic loss of life and struggling with the terror that was brought upon us."

President Joe Biden released a statement too about the shooting, saying he and First Lady Jill Biden are "shocked by the senseless gun violence that has yet again brought grief to an American community on this Independence Day."

"As always, we are grateful for the first responders and law enforcement on the scene. I have spoken to Governor Pritzker and Mayor Rotering, and have offered the full support of the Federal government to their communities," he said. "I also surged Federal law enforcement to assist in the urgent search for the shooter, who remains at large at this time."

"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 added. "I recently signed the first major bipartisan gun reform legislation in almost thirty years into law, which includes actions that will save lives. But there is much more work to do, and I'm not going to give up fighting the epidemic of gun violence."

Illinois Governor J.B. Pritzker later spoke out about the tragedy in a speech on Monday evening.

"The families of six individuals woke up today to join a community celebration of our nation's Independence," he said. They will go to bed tonight less than whole."

"There are no words for the kind of evil that shows up at a public celebration of freedom, hides on a roof and shoots innocent people with an assault rifle," Gov. Pritzker added. "There are no words I can offer to lessen the pain of those families who will no longer associate the 4th of July with the celebration, but instead with grief."

He went on to discuss gun violence, saying, "It is devastating that a celebration of America was ripped apart by our uniquely American plague. A day dedicated to freedom has put into stark relief the one freedom we, as a nation, refused to uphold. The freedom of our fellow citizens to live without the daily fear of gun violence."

This story is developing and will be updated as further details emerge.