Authorities detained a person of interest in the deadly Fourth of July parade shooting Monday evening in Lake Forest, Illinois.

Police detained 22-year-old Robert E. Crimo as a person of interest in the deadly massacre after a brief pursuit, authorities said. A Chicago police officer spotted Crimo and attempted to perform a traffic stop when the 22-year-old fled, authorities said, according to CNN. Crimo, who goes by the name “Bobby,” was believed to be armed and dangerous at the time he was taken into custody.

A day of national celebration turned to tragedy Monday when a gunman killed six people and injured dozens more at a July Fourth parade in Highland Park, Illinois -- leaving the nation grieving yet another mass shooting.

The suspected shooter, identified by authorities as Robert E. Crimo III, used a "high-powered rifle" in an attack that appeared to be "random" and "intentional," police said. They believe the shooter, who was apprehended later Monday, climbed onto a rooftop of a business and opened fire on the parade about 20 minutes after it started.

A gunman opened fire on the Highland Park Independence Day parade, killing at least six people and wounding more than two dozen others in the latest mass shooting incident to terrorize an American community.

The shooter, a white man between 18-20 years old with long black hair, who was last seen wearing a white or blue shirt, opened fire from a rooftop with a high-powered rifle and targeted spectators, according to police. He remained at large as of Monday afternoon.