Flint Police are searching for a man they believe has slain five and attacked seven slightly built or vulnerable African-American men in three months, with no apparent reason other than to kill.

“He’s killed five people,” Flint Police Sgt. J. Leigh Golden said Thursday. “He’s just killing them, not robbing them.”

Police warn that the serial killer appears to be targeting smaller-framed or otherwise vulnerable victims.

The latest victim was Arnold Minor, 49, stabbed to death early Monday on the city’s south side, near Saginaw Street, where several of the assaults have occurred.

On Sunday, Minor and his sister, Stephanie Ward of Flint, had dinner at their brother’s home on the north side, and later visited their mother who lives nearby.

Ward said she last saw her brother around 11 p.m. when she left her mother’s and drove home to the south side of Flint.

Minor realized too late that city buses had stopped running, so he began the 10-mile southward journey home about 1:30 a.m. on foot, his sister said.

“When they found him, he wasn’t far from home,” Ward said. “He bled to death on the street. You don’t know what goes through somebody’s mind to do something like that.”

Police believe at least 10 stabbings in the city since mid-May are the work of one man, whom they would only describe as white with light-colored hair who stands a muscular 6 feet tall or more.

Survivors have told police their attacker approached them with a story about needing help. Some said they were stabbed multiple times without warning.

Officials with the Flint branch of the NAACP said the safety of black people isn’t taken seriously in the city. Frances Gilcreast, the local president, said it’s alarming to learn about serial killings after 12 attacks have occurred. She knew nothing until noon Thursday when she saw a TV news report, she said.