(NewsNation Now) — A 21-year-old man was taken into custody after being named a person of interest in a mass shooting at a July 4 parade in a suburb of Chicago that left at least six people dead and 24 others injured.

About eight hours after the shooting occurred, police took Robert “Bobby” Crimo III of Highland Park into custody after an officer spotted him in a vehicle and he led them in a short pursuit.

While Crimo is not named as a suspect in the shooting, Lake County Sgt. Chris Covelli said officials only release the name of a person of interest after a thorough investigation.

“Calling someone a suspect, a person of interest … It’s synonymous,” he said.

At about 10:14 a.m., a suspect perched on the rooftop of a business in downtown Highland Park began spraying bullets into the gathered revelers below, police said.

The shooting resulted in the deaths of at least six people and injuries to at least 30 others. The ages of those injured ranged from 8-85 years old, officials said. At least “four or five” of them were children, hospital officials said in a news conference Monday evening.

A high-powered rifle was found on the roof of a local business near the area of Second Street and Central Avenue, along the parade route where officials believe the shooter positioned himself.

Following the shooting, the suspect used a ladder attached to the building to flee the scene, Covelli said.

More than 100 officers from multiple agencies worked on the investigation and hours-long manhunt, officials said.

Officials are asking anyone with information, surveillance footage or cellphone footage taken in the area of Second Street and Central Avenue in Highland Park around the time of the shooting to call 800-CALL-FBI (225-5324).

Highland Park is in Lake County, about 25 miles north of downtown Chicago.

Several neighboring communities canceled their holiday festivities in the aftermath of the shooting.

Gov. J.B. Pritzker was aware of the situation Monday afternoon.

“My staff and I are closely monitoring the situation in Highland Park,” the governor tweeted. “State police are on the scene and we have made all state resources available to the community. We will continue working with local officials to help those affected.”

“Jill and I are shocked by the senseless gun violence that has yet again brought grief to an American community on this Independence Day,” President Joe Biden said in a statement. “As always, we are grateful for the first responders and law enforcement on the scene.”

Several witnesses took to social media to document the chaos as crowds began fleeing the area when the shooting started. Debbie Glickman, a Highland Park resident, said she was on a parade float with coworkers and the group was prepared to turn onto the main route when she saw people running away from the area.

“People started saying, ‘There’s a shooter, there’s a shooter, there a shooter,’” Glickman told the Associated Press. “So we just ran. We just ran. It’s, like, mass chaos down there.”

NewsNation affiliate WGN and the Associated Press contributed to this report.