Riley Strain's Family Order Second Autopsy, New Details Not Adding Up

Riley Strain's grieving family is ordering a second private autopsy for him after the first found no signs of foul play -- this after new details emerged about his death.

The 22-year-old didn't have his cowboy boots, pants or wallet when he was pulled out of the Cumberland River 2 weeks after disappearing from Luke Bryan's Nashville bar on March 8.

But, Chris Dingman, a family friend serving as their spokesperson, told NewsNation Riley was wearing all those items the night he went missing ... leading them to believe his death was more than accidental.

Also, the preliminary report confirmed the absence of water in his lungs ... raising serious concerns he may have been dead before entering the water, and casting doubt on the assumption he drowned.

Dingman explains the additional autopsy from a private independent company is driven by the family's need to address all those lingering questions surrounding Strain's death.