A 21-year-old arrested in connection with a mass shooting at a Highland Park Fourth of July parade has been charged with murder, authorities announced Tuesday.
The alleged gunman faces seven counts of first-degree murder in connection with the shooting that left seven people dead and dozens of others injured.
Lake County State's Attorney Eric Rinehart says that the suspect in the shooting will face additional charges in the coming days, but says that his office will seek a mandatory life sentence.
"We anticipate dozens more charges centering around each of the victims," he said.
Rinehart emphasized that the suspect will face attempted murder, aggravated battery and a series of other charges in connection to the shooting, and that his office will seek to keep the suspect held without bail in connection with the case.
News of the charges comes as police released new details on what they believe happened as the shooting unfolded, saying the suspect planned the shooting for "several weeks."
Lake County Major Crimes Task Force spokesman Sgt. Christopher Covelli said 21-year-old Robert "Bobby" E. Crimo III 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. (NOTE: NBC 5 will not be naming the suspect again in this story)
"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, but a motive for the shooting remains unclear.
"[The] shooting appears to be completely random," Covelli said, adding that "we have no information to suggest at this point it was racially motivated, motivated by religion or any other protected status."
Covelli said the alleged gunman put on a disguise 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.
Covelli said there were "no indications" anyone else was involved in the shooting.
The shooting happened at 10:14 a.m. CT in the area of Central Avenue and 2nd Street in downtown Highland Park during the city's Fourth of July parade, authorities said.
In separate social media videos, several gunshots could be heard, followed by a pause and another round of gunfire. In some videos, more than 50 shots are heard.
Larry Bloom, who was in the area when shots began, said at first spectators thought the "popping" sound was part of the parade.
"You heard like a 'pop, pop, pop,' and I think everybody kinda thought maybe it was a display on one of the floats and then it just opened up," Bloom said.
"I was screaming and people were screaming," Bloom said. "They were panicking and they were just scattering and I, you know, we didn't know. You know, it was right on top of us."
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."
Illinois Gov. JB Pritzker asked for prayers for the families of the deceased and for those who were injured in the shooting.
"There are no words for the kind of monster who lies in wait and fires into a crowd of families with children celebrating a holiday with their community," Pritzker said in a statement. "There are no words for the kind of evil that robs our neighbors of their hopes, their dreams, their futures. There are no words I can offer to lift the pain of those they leave behind. Please know that our state grieves with you, that MK and I grieve with you."
While the shelter-in-place order for Highland Park residents has been lifted, police are still urging people to avoid the city's downtown area while the investigation continues.
Police continued to urge witnesses to submit any photos or videos of the scene that may be of use in their investigation.