A gunman opened fire from a rooftop into the Highland Park Independence Day parade Monday in a "completely random" attack that officials say killed at least six people and wounded dozens of others.
Here's what we know so far about what happened. (Check back for the latest updates)
What We Know About the Shooting So Far
The shooting happened at 10:14 a.m. in the area of Central Avenue and 2nd Street in downtown Highland Park during the city's Fourth of July parade, authorities said.
In video posted on social media by parade attendees showing the moment of the shooting, several gunshots could be heard, followed by a pause and another round of gunfire. In some videos, more than 50 shots are heard.
Police released new details Tuesday on how the mass shooting unfolded, saying the suspected gunman had been planning the attack "for several weeks" and dressed as a woman to help flee the scene.
Lake County Major Crimes Task Force spokesman Sgt. Christopher Covelli said the 21-year-old suspect had legally purchased a high-powered rifle before he climbed a fire escape at a business along the suburban Chicago parade route and fired more than 70 times from the rooftop.
"We do believe [the suspect] pre-planned this attack for several weeks," Covelli said. "He brought a high-powered rifle to this parade, he accessed the roof of a business via a fire escape ladder and began opening fire on the innocent Independence Day celebration goers."
Authorities said a gun found at the scene and another rifle found in the 21-year-old's vehicle at the time he was arrested were registered in his name and legally purchased.
Covelli said the alleged gunman dressed in women's clothing to "conceal his facial tattoos and his identity," and escaped with others fleeing the chaos.
"He dropped his rifle and he blended in with the crowd and he escaped," Covelli said, adding that he "blended right in with everybody else as they were running around almost as he was an innocent spectator as well."
He went to his mother's home near the parade in Highland Park, borrowed her vehicle and was taken into custody hours later after a witness reported seeing the vehicle in the North Chicago suburb.
What We Know About the Victims
The seventh person died Tuesday afternoon, according to Covelli.
Details are beginning to emerge about the victims.
At least two have been identified so far, including Nicolas Toledo, a grandfather whose family says "saved all of our lives," and Jacki Sundheim, a "cherished member" of the North Shore Congregation Israel staff.
NorthShore University HealthSystem confirmed just after 5:30 a.m. Tuesday that a total of 38 people sought treatment from their hospitals following the shooting. By Tuesday morning, eight patients were still receiving treatment. The hospital had no updates on their conditions.
Northwestern Medicine Lake Forest confirmed around 8 a.m. Tuesday that their hospital also treated nine patients, five of which were discharged Monday. Six of the nine people suffered gunshot-related wounds while three suffered fall-related injuries. The gunshot victims were all adults, the hospital said, but the ages of the others weren't immediately known. All were listed in fair to good condition, according to Chief of Media Relations Chris King.
Dr. David Baum, who attended the parade, helped treat those who were injured in the shooting.
"The bodies that I saw, it was not an image that anyone who's not a physician would have an easy time processing," said Dr. Baum.
"There were people who were immediately killed with horrific gunshot wounds."
What We Know About the Suspect
Police identified the person of interest in the shooting as 21-year-old Robert "Bobby" E. Crimo III. He was taken into custody Monday evening following a police pursuit, but no charges had been filed as of Tuesday morning.
Authorities said the suspect's vehicle was located in North Chicago and officers attempted to stop him before he fled the scene, leading police on a brief pursuit before coming to a stop. He was taken into custody "without incident," police said, and was being taken to the Highland Park Police Department for questioning.
Police had said the suspect was believed to be driving a 2010 silver Honda Fit with the Illinois license plates DM80653. Video from NBC's Sky 5 chopper showed a vehicle of that make and model stopped at an intersection in Lake Forest with visible damage.
A heavy police and SWAT presence was seen hours earlier in an area where Crimo is believed to have lived, according to footage captured by NBC 5 in Highland Park.
The suspected gunman in the mass shooting was described by Highland Park police as a white man with a small build and "longer" black hair. He is wearing a white or blue T-shirt, according to Highland Park Police Cmdr. Chris O'Neill.
NBC 5 Investigates discovered new information on the 21-year-old suspect and how police found him.
The man was identified due to the rapid trace by the Bureau of Alcohol, Tobacco and Firearms, which took DNA recovered from the rifle found at the scene.
The Investigates team also found the 21-year-old's extensive online presence, which contains "disturbing" imagery, videos and posts.
Covelli said the suspect remained in custody as of 11:30 a.m. Tuesday, adding that there were "no indications" anyone else was involved in the shooting.
What We Know About the Motive
Police said the shooting appears "completely random" but also "intentional."
"We have no information to suggest at this point it was racially-motivated, motivated by religion or any other protected status," Covelli said.
Latest Guidance for Residents
Police had asked residents late Monday afternoon to remain sheltered in place in the area from Green Bay Road to Laurel, to St. Johns to Elm Place.
"Individuals outside of this area no longer need to shelter in place, however we urge everyone to remain vigilant and immediately report suspicious behavior," officials said in an alert.
On Tuesday morning, police asked the public to avoid downtown Highland Park as investigation continues.
The FBI Chicago Public Affairs Team said the shooting in Highland Park "remains an active and ongoing investigation."
"FBI-Chicago is requesting that any individuals with information regarding the shooting incident in Highland Park, IL on July 4, 2022 please submit the information to: 1-800-CALLFBI."
Anyone with photos or video of the incident is being asked to turn it into police.
"Everyone in the Highland Park area is asked to report any suspicious activity by calling 911, or Highland Park Police at 847-432-7730," Covelli said. "To report any delayed information about this incident, the FBI has established a tipline at 800-CALL-FBI."
Reaction From Officials
Highland Park Mayor Nancy Rotering said on NBC's "Today" that while she is currently waiting for charges against the person of interest in the shooting, her greater focus Tuesday morning "is how my community is feeling, the unbelievable sadness, the unbelievable shock. This tragedy never should’ve arrived at our doorsteps."
Rotering revealed that she knew the suspect from her time as a Cub Scout leader and she wonders, "How did somebody become this angry, this hateful, to then take it out on innocent people who literally were just having a family day out?"
Rotering talked about hearing from mayors of towns who have experienced their own gun violence tragedies, and said she told them yesterday, "I never thought I would be one of those mayors. Well, none of us ever think we will be one of those mayors."
President Joe Biden in a statement Monday afternoon said 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," Biden 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. 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 Gov. JB Pritzker spoke to media Monday afternoon, saying, "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."
"There are no words I can offer to lessen the pain of those families who will no longer associate the Fourth of July with celebration, but instead with grief," Pritzker said, adding, "It is devastating that a celebration of America was ripped apart by our uniquely American plague."
Sen. Tammy Duckworth said in the same media address that when she listened to the sound of the gunfire in one of the videos, "the last time I heard a weapon with that capacity, firing that rapidly on a Fourth of July was Iraq. It was not the United States."
Chicago Mayor Lori Lightfoot said her "heart aches for the people of Highland Park" in a statement released Tuesday, adding that "we must continue to lift up this community, the victims, and their families in prayer."
"Thanks to the heroic efforts of law enforcement, a person of interest in the horrific Highland Park mass shooting is in custody. I hope this provides a bit of solace to those who are deeply grieving tonight in the wake of today's unspeakable tragedy," Lightfoot said.
"Gun violence does not respect geographic boundaries or socioeconomic differences. It is a plague that affects us all. Whether it is Back of the Yards, Englewood, West Garfield Park, Uvalde, Buffalo, or now Highland Park, none of us are immune, and all are vulnerable without a federal effort to take weapons of war out of the hands of civilians. It can be done, it must be done, and we must continue to move toward that goal with all deliberate speed. We cannot be truly free unless we are relentlessly brave."
Cook County Board President Toni Preckwinkle said the county "stands with Lake County and the Highland Park community."
"While the situation remains fluid, we are standing by to support law enforcement and our neighbors to the north in any way we can," Preckwinkle said. "We will continue to monitor the situation and extend our resources and overall support to the people of Highland Park. We must, we all must, focus on stemming the flow of illegal guns and implementing common sense gun laws. My continued thoughts are with the families and loved ones who have lost someone and for everyone struggling to comprehend today’s latest senseless act of gun violence."