"It was a snowstorm at the time," Sergeant Brandon Danielson told the Des Moines Register: "He left with no shoes, no socks, no keys, no car."
Noise from the freezer units could have made it difficult for anyone to hear him crying for help. "It's so loud, there's probably no way anyone heard him," Sgt. Danielson said.
During the search authorities contacted family members, scoured nearby detention centres and attempted to trace him through the US Immigration and Customs Enforcement agency, as Murillo-Moncada had been deported to Honduras before returning to the US.
The store was shuttered in 2016. The remains were found in January and an autopsy found no signs of trauma. The death was ruled accidental.