Torrence won silver for the USA at the World Relay Championships in 2014 and claimed another second-placed finish at the Pan American Games in 2015.
He switched allegiances to represent Peru at the 2016 Rio Olympics.
"Detectives learned that there were no obvious signs of foul play," a police statement said.
American runner Leo Manzano, who won silver in the 1500m at the 2012 London Olympics, said: "It saddens me to hear about my former team-mate David Torrence. My heart goes out to him and his family."
Canadian track and field Olympian Nate Brannen said: "In complete shock to hear of the passing of David Torrence. Great guy and friend. He will be deeply missed."
American middle-distance runner David Torrence has been found dead in a swimming pool in Arizona at the age of 31.