The man charged with killing seven people when he unleashed a hail of bullets on an Independence Day parade from a rooftop in suburban Chicago legally bought the high-powered rifle used in the shooting and four other weapons, despite threatening violence, police said.

Robert E. Crimo III was charged with seven counts of murder Tuesday in the shooting that sent hundreds of marchers, parents and children fleeing in fear and set off an hourslong manhunt in and around Highland Park, an affluent community on the shores of Lake Michigan. Investigators have yet to identify a motive.

Prosecutors have promised to seek dozens more charges, and Crimo is expected to make his first court appearance on Wednesday. His attorney said he intends to enter a not guilty plea to all charges.

A rifle “similar to an AR-15" was used to spray more than 70 rounds from atop a commercial building into the parade crowd, a spokesman for the Lake County Major Crime Task Force said.

A seventh victim died of their injuries Tuesday. More than three dozen other people were wounded in the attack, which Task force spokesman Christopher Covelli said the suspect had planned for several weeks.

Illinois state police, who issue gun owners’ licenses, said Crimo applied for a license in December 2019, when he was 19. His father sponsored his application.