DETROIT — A person waiting for the bus and another walking their dog were among four people shot, three fatally, by a man who appeared to fire randomly over about 2 1/2 hours in Detroit, police said.

Police arrested a suspect Sunday night after an hourslong manhunt involving multiple federal agencies. Police Chief James White said tips led officers to the suspect, but he did not immediately release more information about the suspect or arrest.

White earlier said investigators traced all four early Sunday shootings to one firearm but believed them to be random because there was no apparent connection among the victims.

He said police discovered a woman in her 40s who had been shot multiple times around 4:45 a.m. Sunday. While officers were investigating that fatal shooting, a witness reported a 28-year-old man had been shot multiple times nearby, White said.

A third victim, a woman in her 40s, was found in the area around 6:50 a.m. She died after being shot multiple times, police said.

Around 7:10 a.m., an elderly man reported he saw a man peering into vehicles. When the elderly man told the person to get away from the cars, the gunman fired at the elderly man, who was shot once and survived, police said.

White and Mayor Mike Duggan had urged residents Sunday to be alert and call police with any information.

“The suspect already shot four people. Please call immediately. … Someone out there knows who this is,” Duggan said.

Duggan later credited “critical information from the community” and multiple law enforcement agencies with helping Detroit police take the suspect into custody.

“As we mourn our three neighbors who were killed, we should take the time to appreciate all the men and women in law enforcement whose work today made sure no other families will suffer at the hands of this shooter,” Duggan tweeted.