The man believed to have killed six people and wounded dozens more at an Independence Day celebration near Chicago planned the attack weeks in advance and dressed in women's clothing to help him escape, according to authorities.
Police apprehended 21-year-old Robert "Bobby" Crimo III on Monday evening, hours after the attack, and suspect that he was solely responsible for the mass shooting at a July Fourth celebration in Highland Park, Illinois, which killed six people and injured more than 30.
At a press conference Tuesday, Sgt. Christopher Covelli of the Lake County Major Crime Task Force said the alleged shooter "pre-planned this attack for several weeks."
"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," Covelli said.
Covelli noted that the alleged shooter "was dressed in women's clothing" to "conceal his facial tattoos and his identity" and to help him blend into the crowd.
The rifle Crimo allegedly used was legally purchased in Illinois, according to Covelli, with him firing over 70 rounds of ammunition into the crowd at the parade.
"Following the attack, Crimo exited the roof, he dropped his rifle, and he blended in with the crowd and he escaped," Covelli continued. "He walked to his mother's home, who lived in the area."
Crimo, who is said to have borrowed his mother's car, was spotted on the highway by a member of the community. A Chicago police officer stopped him and took him into custody.
A second rifle was found in the escape vehicle, with authorities believing the alleged shooter had also purchased that weapon. A motive has yet to be determined.
Multiple law enforcement agencies worked on the case, including local authorities, state police, the Lake County Major Crime Task Force and the Federal Bureau of Investigation.
Highland Park Mayor Nancy Rotering said at a press conference Monday that "our community was terrorized by an act of violence that has shaken us to our core."
"Our hearts go out to the families of the victims at this devastating time. On a day that we came together to celebrate community and freedom, we are instead mourning the tragic loss of life and struggling with the terror that was brought upon us," Rotering said.
Thus far, two of the six fatalities have been identified: Nicolas Toledo, a retired grandfather in his 70s, and Jacki Sundheim, a longtime member of North Shore Congregation Israel.
The Highland Park shooting was just one of several other shootings in Chicago over the weekend. Chicago Police say that at least 71 people were shot over the July Fourth weekend, and eight were killed.
ABC7 reports that 19 people were killed and over 100 wounded during the Fourth of July weekend in 2021.