According to a 911 caller, Cortner may have been shot at least three times.
It wasn’t clear whether the shooting happened inside or outside.
“There was a front door open. We don’t know if he was shot from the outside or inside,” Clingner said.
South Euclid Avenue at Bancroft Street was blocked while crews investigated.
Many people were outside the complex watching as police went in and out of the complex.
One woman who lives nearby said while she didn’t hear any gunshots, she couldn’t believe how many officers flooded the area.
“It’s sad, it’s just sad, it’s very sad,” she said.
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Anyone with information is urged to call police at 937-333-COPS(3677), or to remain anonymous, call Miami Valley Crime Stoppers at 937-222 STOP(7867).