An Illinois man charged with killing seven people and injuring dozens more at a 4th of July parade in a Chicago suburb in 2022 changed his plea to guilty moments before his trial was set to begin on Monday.

Robert Crimo III, 24, withdrew his not guilty plea and entered a guilty plea to 21 counts of first degree murder — three for each of the victims he murdered — and 48 counts of attempted murder, The Associated Press reported. Prosecutors had previously dropped 48 counts of aggravated battery before jury selection began last week.

Investigators say surveillance footage and witnesses will show how Crimo III climbed a Highland Park fire escape and opened fire, then escaped the scene disguised as a woman, likely an attempt to hide his obvious facial tattoos, as CrimeOnline reported. Authorities say he confessed to police but later retracted that confession.

After the shooting, Crimo III walked to his mother’s nearby home and borrowed her car, apparently intending to go to another holiday celebration in Wisconsin and kill more people, but he changed his mind and returned to Illinois.

Crimo’s trial was delayed numerous times, first because he wanted to fire his public defenders and represent himself (he reversed that decision) and later when he backed out of a deal that would have seen him plead guilty to about half the charges.

Robert Crimo Jr., the suspect’s father, pleaded guilty in November 2023 to seven counts of misdemeanor reckless conduct for helping his son buy the rifle he used in the mass shooting, despite a relative reporting  to police that Crimo III had threatened to “kill everyone” and himself. Crimo Jr. issued a statement last week saying he loves his son and supports “his decision to go trial in this case.”

Crimo III entered his new plea before the previously selected jurors were brought into the courtroom on Monday, The AP said.

“Our community may never heal from the defendant’s calculated and heinous actions that destroyed so many lives,” Lake County State’s Attorney Eric Rinehart told reporters after court. “He received nothing in exchange for his plea. We were 1000 percent ready to go to trial and prove him guilty to the jury. We have been working for years to prepare our evidence.”

Crimo is all but certain to spend the rest of his life in prison. His sentencing has been set for April 23. Prosecutors said that survivors will get a chance to address the killer at the sentencing hearing.

A spokesperson for a lawfirm representing dozens of survivors in a lawsuit told reporters that the survivors “have all gone hoe to process” after the surprise guilty plea.

“They each expressed an individual and a collective sense of relief, but today was a very emotional event and they are asking for some time and space to come to terms with what happened,” said Jennifer McGuffin with Romanucci & Blandin.

Katherine Goldstein, 64; Jacquelyn Sundheim, 63; Stephen Straus, 88; Nicolas Toledo-Zaragoza, 78; Eduardo Uvaldo, 69; and married couple Kevin McCarthy, 37, and Irina McCarthy, 35, were killed in the mass shooting. The wounded ranged in age from their 80s to an 8-year-old boy was was left partially paralyzed.