BATON ROUGE, La. >> The slayings of two black men in Baton Rouge last week were likely racially motivated, police said today, and a suspect — a 23-year-old white man — was in custody. In both shootings the gunman fired from his car then walked up to the victims as they were lying on the ground and fired again multiple times.

The suspect, Kenneth Gleason, was being held on drug charges. Authorities didn’t immediately have enough evidence to arrest him on charges related to the killings, but the investigation was ongoing, Baton Rouge Sgt. L’Jean McKneely told The Associated Press.

“The victims were … ambushed,” McKneely said. “There is a strong possibility that it could be racially motivated.”

McKneely said shell casings from the shootings linked the two slayings, and a car belonging to Gleason fit the description of the vehicle used in the killings. He said authorities had collected other circumstantial evidence but he wouldn’t say what it was.

Neither victim had any prior relationship with Gleason. It wasn’t immediately clear if Gleason had an attorney or when his first court appearance would be.

The shootings happened about five miles from each other. The first occurred Tuesday night when 59-year-old Bruce Cofield, who was homeless, was shot to death. The second happened Thursday night when 49-year-old Donald Smart was gunned down while walking to his job as a dishwasher at a cafe popular with Louisiana State University students, Mckneely said.

Smart’s aunt, Mary Smart, said she was still dealing with the shock of her nephew’s death.

“I’m feeling down and depressed. My nephew, I love him, and he was on his way to work and that makes it so sad,” she said in a telephone interview Sunday. “He was always smiling and hugging everybody. A lot of people knew him.”

Smart had a son and two daughters, she said.

She declined to comment on police allegations that her nephew might have been shot because of the color of his skin.

“I cannot say,” she said. “Only God knows.”

No one answered the door at Gleason’s house in a quiet neighborhood of mostly ranch-style homes with well-kept lawns, located about 10 miles from the sites of the shootings.

“He looks like any clean-cut American kid,” said neighbor Nancy Reynolds, who said she didn’t know Gleason or his family. She said it was “hard to believe this sort of thing is still happening.”

Two of Gleason’s cousins said they couldn’t believe he had anything to do with the killings.

“He had no problems with any person,” said Garrett Sing, 37. “He had black friends, white friends, Asian friends. He made friends with anyone.”

Another cousin, 33-year-old Barton Sing, described Gleason as a “good kid” and recalled how his cousin recently asked him to teach him how to bow hunt.

“He said he never liked guns. That’s why he wanted to get into archery,” Sing said. “He’s the last person I’d think to do something like this.”

Gleason didn’t appear to have any active social media profiles. A spokesman at Louisiana State University said a student by that name attended the university from the fall of 2013 to the fall of 2014 before withdrawing. He had transferred to LSU from Baton Rouge Community College, the spokesman, Ernie Ballard, said.

East Baton Rouge District Attorney Hillar Moore said a judge could issue a ruling on bond for Gleason later Sunday. Moore wouldn’t comment on what led investigators to him.

“We’re actively investigating right now,” Moore said.

Detectives searched Gleason’s home on Saturday and found 9 grams of marijuana and vials of human growth hormone at his house, according to a police document. After Gleason was read his Miranda rights, he claimed ownership of the drugs, the document said.

Louisiana’s capital, a city of 229,000, is known for its championship college football team and its political scene. A year ago, racial tensions roiled the city when a black man was shot to death by white police officers outside of a convenience store. About two weeks later, a black gunman targeted police in an ambush, killing three officers and wounding three others before he was shot to death. The city is about 55 percent black and 40 percent white.

Smart consistently showed up for his overnight shift as a dishwasher at Louie’s Cafe in a spotless white T-shirt and bright white Nike tennis shoes, The Advocate newspaper reported.

“I’ve seen 26 years of folks washing dishes in a busy diner and this guy is untouchable,” Louie’s general manager, Fred Simonson, was quoted as saying. “When you have an employee like Donald, he’s the type of person who’s going to make the person next to him better.”