Police arrest suspect after gunman kills six at US July 4 parade

First responders take away victims from the scene of a mass shooting at a Fourth of July parade on July 4, 2022 in Highland Park, Illinois.

Police arrested a suspect Monday after a mass shooting left six dead at a US Independence Day parade in a wealthy Chicago suburb, casting a dark shadow over the country's most patriotic holiday. 

Robert Crimo, 22, was identified as a "person of interest" and became the target of a massive manhunt across the town of Highland Park in Illinois, where a rooftop gunman with a high-powered rifle turned a family-focused July 4 parade celebration into a scene of death and trauma.

Firing into the holiday crowd, the shooter caused scenes of chaos as panicked onlookers ran for their lives, leaving behind a parade route strewn with chairs, abandoned balloons and personal belongings.

Emergency officials said around two dozen people, including children, were treated for gunshot injuries, with some in critical condition.