An unidentified suspect has been charged with murder in the crossbow death of a Michigan man, who was found dead in his family’s driveway by his twin brother.

Marcus Olmstead, 20, of Norton Shores, was killed Wednesday night, according to police. His death was ruled a homicide Thursday morning.

Officials with the Norton Shores Police Department said in a news release Thursday that a suspect in Olmstead's slaying was located in Grand Rapids and arrested. The alleged killer was booked into the Muskegon County Jail.

Marcus Olmstead is pictured below, at left, with his brother, Maxwell Olmstead.

Nyoky Bull, 20, of Grant, was arrested Thursday on a charge of murder of a non-family member with a weapon described as "other," the jail log states. Bull was being held without bond.

The suspect’s relationship to the victim was not disclosed, but police officials said the killing was not random and that the two knew one another. The  motive for the slaying was unclear.

Olmstead's stepmother, Michelle Olmstead, described her stepson to WOOD-TV in Grand Rapids as "childlike." She said he had spent the hours prior to his death playing fantasy board games, like Dungeons and Dragons, at a friend's house.

After he got home, he messaged back and forth with a girl and then went outside to wait for her, Michelle Olmstead said. No one heard him being killed.

"About an hour later, his twin (Maxwell Olmstead) came home from work, found him lying there in the driveway," Michelle Olmstead told the news station. "He goes over there, starts shaking him, rolls him over and that's when he realizes there's an arrow sticking out of his abdomen, like something you'd see in a movie or on CSI or something."

Michelle Olmstead, a registered nurse, said she tried saving Marcus, but he was already gone, WOOD-TV reported.

She described the victim as a young man who suffered from some emotional problems, but was outgoing, kind and gentle, the news station said. She said his proudest moment was probably touring Europe during his senior year with his high school choir.

His brother, who posted on Facebook about his twin's death, is devastated, Michelle Olmstead said.

"Max had the strongest bond to Marcus (of) anybody," she said. "He's devastated. He's very angry. He's a 20-year-old young man. He's got a flow of emotions. He lost half of himself -- his twin."

Maxwell Olmstead posted a photo of himself with his brother, as well as one of the twins with their father, Rob Olmstead.

“I will always love you, my brother,” he wrote.