Police in a Des Moines suburb are calling the weekend death of a man “suspicious.” Fourty-nine-year-old Randy Warrens of Clive was found unresponsive in a parking lot near his apartment complex at 2 a.m. on Saturday.

Clive Police Chief Michael Venema says a passerby reported a man down to an employee of a nearby bar. That employee called police.

“What makes this suspicious is the fact that, right now, we don’t have anyone who was actually present at the time the injury actually happened,” Venema said. “Mr. Warrens was found down in a parking lot with a head injury and at this point, there were no witnesses to whatever happened.”

The passerby who reported finding Warrens left the scene before police arrived. Warrens had not been at the nearby bar and it’s unclear what he’d been doing that night. “We are still piecing together where he had been, which is why we’re asking anyone who may have known him or been with him that evening, to let us know,” Venema said.

An autopsy is scheduled for today. Venema said it’s unknown if Warrens’ head injury was caused by a fall or an assault.