(NewsNation) — When his body was recovered from the Cumberland River, Riley Strain was not wearing his pants, wallet or cowboy boots he had on the night he went missing, leaving his family and friends grappling for answers, according to a family friend.

“The only thing that was found with him, as the police stated in the report, was the watch and the shirt,” Chris Dingman said in a Wednesday interview on NewsNation’s “Elizabeth Vargas Reports.”

The University of Missouri student, 22, was last seen March 8, when he vanished during a night out with friends in downtown Nashville. His body was found two weeks later in the Cumberland River after a massive search effort.

On Saturday, March 23, the Metro Nashville Police Department confirmed to NewsNation affiliate WKRN that Strain’s preliminary autopsy had been completed, adding his death continued to appear “accidental,” with no foul play-related trauma. 

However, the family has ordered a second autopsy in hopes of obtaining more information.

“The family deserves more answers than we have,” Dingman stated.

One puzzling detail from the first autopsy was a medical examiner stating Strain had no water in his lungs, raising questions about the circumstances of his death.

“Usually, water in the lungs means that they were alive when they went into the water,” Dingman said, expressing concern over the lack of clarity in the investigation.

Despite ongoing inquiries, there are still individuals the police have yet to interview, including those from a homeless encampment near where Strain’s body was found.

“I think there’s somebody out there that knows what actually happened that night,” Dingman said.

Strain’s funeral is scheduled for Friday in his hometown.