The 19-year-old suspect turned himself in at the Homicide Unit on Tuesday. Police say his identity will be provided when processing has been completed.
A second suspect remains on the loose.
Wilsey was gunned down shortly before 9 p.m. on Monday, November 28th, on the 6200 block of Brous Street in the Mayfair section of Philadelphia.
Wilsey lived on Cottman Avenue and was a ninth grader at Northeast High School.
According to police, Wilsey and his friend were walking to a nearby store when two men approached them.
The friend tells Action News, "We saw two men walk up from my left and they had guns, and we just turned around and started running."
"They just started shooting," the friend said. "They didn't say anything. They didn't stop to talk to us. They just started shooting."
Wilsey was shot three times, and one of the bullets went through his heart.
"He didn't make it in time to run," the friend said.
Neighbor Chrissy Calel heard the gunfire.
"You don't expect to hear the gunshots. You always think it's fireworks or something. I realized after the first shot, I was like 'get away from the window,'" Calel said.
Wilsey was able to run a few feet before collapsing.
"After I heard the gunshots, I heard him screaming," the friend said.
The friend was uninjured and ran for help. He returned minutes later with an adult to a grisly scene.
"Me and him went outside to go check on him, and we seen him get picked up by the cops for a scoop and run," the friend said, referring to the Philadelphia police policy of immediately transporting shooting victims to the hospital rather than waiting for medics.
Wilsey was taken to Aria Health Torresdale, where he died.
"I thought he was going to make it. I was praying the whole time," the friend said. "I just want him back. I just want him back. I miss him so much."
Frank Myers, another close friend and classmate of Wilsey's at Northeast High, said he was told of the shooting at school.
"I went to school," said Myers. "They took me inside a classroom and they said, 'You know, your friend Ian got shot,' and I'm like, 'That's fake.' I couldn't really believe it."
After he briefly visited Wilsey's family and saw Wilsey's brother Charles, Myers said he knew it was true.
"I went in there and saw Charles crying. He's not the person to cry, and I really saw him crying, and I was like, that's a shame, man," Myers said.