At least seven people were killed after a gunman drove around a Michigan city randomly shooting people in parking lots of an apartment complex, a car dealership and a restaurant Saturday night, authorities said.

Authorities said a 45-year-old white man was arrested early Sunday in downtown Kalamazoo following a manhunt after the shooting spree began. The man was arrested without incident and has yet to be identified.

A 14-year-old girl was among five people killed outside a Cracker Barrel restaurant and a father and son were killed outside a Kia dealership, Kalamazoo County Undersheriff Paul Matyas said. A woman was shot outside an apartment complex as well. She was in serious condition as of early Sunday, Matyas said.

Matyas said earlier that authorities did not believe the shootings were targeted at specific people, describing them as "our worst case scenario."

"These are random murders," he said.

He described a terrifying rampage that began about 6 p.m. in the parking lot of the apartment complex in Richland Township on the easte edge of the Kalamazoo County, where the woman was shot and seriously wounded.

About four hours later and 15 miles away, the father and son were fatally shot while looking at cars. Fifteen minutes after that, five people were shot in the parking lot of the Cracker Barrel along Interstate 94, including the teenager.

The suspect was arrested about 12:40 a.m., authorities said. Matyas told WWMT-TV that the man did not resist when approached by law enforcement officers, and that weapons were found in his vehicle.

"The threat to the public is over," Matyas said.

Michigan State Police Lt. Dale Hinz called the shooting spree “incomprehensible,” according to Fox 17 Online.

Kalamazoo, with a population of about 75,000, is about 160 miles west of Detroit. It is home to Weste Michigan University and the headquarters of popular craft beer maker Bell's Brewery. The city also is known for the anonymously funded Kalamazoo Promise program, which has paid college tuition of students who graduate from Kalamazoo Public Schools for more than a decade.

The Associated Press contributed to this report.