The city of Detroit was on edge after police said a single gunman randomly shot four victims, three fatally, in 2 hours and 25 minutes Sunday morning.
The sole survivor of the killing rampage, an 80-year-old man, described being shot after spotting the suspect looking into cars and confronting him, police said.
Detroit police said Sunday night that the suspect is now in custody, and an investigation is in the early stages.
An all-hands-on-deck search involving multiple law enforcement agencies -- including the FBI, the Bureau of Alcohol, Tobacco, Firearms and Explosives, and the Department of Homeland Security -- took place Sunday afternoon after police determined the same gun was used in all four shootings, authorities said.
During a news conference Sunday afternoon, Detroit Police Chief James White had described the suspect as a Black man in his mid-20s to early 30s, wearing all black, including a black Carhartt jacket with a hood.
"Evidence suggests a single suspect," White said. "At this time, we believe this to be a random act. There does not appear to be any relation between any of the crimes."
He said one of the victims was shot while waiting for a bus and another was shot while out walking a dog. Three of the four victims were fatally shot, police told Detroit ABC affiliate WXYZ.
The shooting began at 4:45 a.m. when a 40-year-old woman was discovered shot multiple times in a neighborhood on the west side of Detroit, the chief said. Police said the woman died from her injuries.
While officers were investigating the shooting, a witness walked up and informed them of another victim nearby, White said. Police found a 28-year-old man who had also been shot multiple times, the chief said. He also died from his injuries.
At 6:50 a.m., the third victim, a woman in her 40s, was found shot multiple times, also on the west side of the city, and died, White said.
And at 7:10 a.m., the fourth victim, an 80-year-old man, was shot after he spotted the suspect peering into the windows of vehicles and confronted him, White said.
"When he told him to get away from the vehicles, he turned and fired at him, striking him once," said White, adding that the victim was shot in the arm.
The octogenarian victim was in stable condition at a hospital Sunday night, police said.
The names of the victims were not immediately released.
White said the suspect did not rob or attempt to rob any of the victims.
Using technology, investigators were able to quickly analyze shell casings from each of the crime scenes and determine that the same gun was used in all four shootings, White said.
"We have mobilized all of our technology, our personnel, our intelligence and our community assets to investigate these incidents. We are currently searching to apprehend the suspect," White said, adding that law enforcement helicopters were also scouring the city.
"To the families and friends of these victims, we will continue to work to get this suspect into custody," White said.
Detroit Mayor Mike Duggan pleaded for the public's help in catching the suspect. He asked people to study the surveillance photo released of the armed-and-dangerous perpetrator and to contact police if they see him. He said anyone who comes in contact with the suspect should not attempt to approach him.
He said the most important thing that can happen is that someone who knows the suspect or has a relationship with him comes forward to law enforcement immediately before he surfaces and strikes again.
"Nobody in this department wants a violent confrontation with this individual," Duggan said. "It's not safe for our officers, it's not safe for the perpetrator, it's not safe for civilians in the area."