The bodies of Mafia hit victims are expected to keep resurfacing as a reservoir near Las Vegas dries out.
A barrel containing the skeletal remains of a man who police believe died of a gunshot wound were discovered by boaters last week in Lake Mead.
The site is around half an hour from the famous strip, which was originally founded in the Nevada desert by the mob to get around US gambling laws.
Gangsters are said to have used the waters to dump murder victims and potentially other secrets.
Dispatching bodies in a barrels and drums was a mob trait in decades gone by.
John 'Handsome Johnny' Roselli, a mid-1950s Las Vegas mobster disappeared in 1976 and a few days later his body was found in a steel drum off the coast of Miami.
Investigators say the shoes and clothing on the recent remains place the death in the mid-70s or early 80s as they were available at Kmart stores during that time.
The lake is drying out thanks to an historic drought.
Homicide detective Lt Ray Spencer told local media further research is being undertaken to study the corroded metal of the barrel.
"It's going to be a very difficult case," he told CBS News in Las Vegas.
"I would say there is a very good chance as the water level drops that we are going to find additional human remains."
A second body was indeed found over the weekend.
Two sisters, Lindsey and Lynette Melvin, were out paddle-boarding when they spotted bones.
The National Park Service, which patrols Lake Mead, said: "The investigation is ongoing. No further information is available at this time."
However, police said there is no evidence so far to suggest that death is suspicious.
"At first I thought it was a bighorn sheep and then we started digging around a little bit and as we discovered the jaw, we realised it was human remains," Lindsey told CBS.
"For the longest time I was in disbelief. Like I did not think that we actually found human remains," Lynette added.
The lake is on the border with Arizona and was created by the Hoover Dam in the 1930s.
The water levels are currently at their lowest for at least a millennium.
Among the most famous unsolved Vegas hits involved gangster Bugsy Siegel, who opened the Flamingo in 1946 on what would later become the strip.
The following year he was shot dead and his assassin never caught.
