But the most ominous detail was this: The leg was cleanly cut at the thigh and the foot.
"We don't know the cause and manner of death," said St. Petersburg police Maj. Mike Kovacsev, who commands the city's detectives. "But obviously someone went to great lengths to dismember this body."
St. Petersburg police said the leg belonged to a "heavyset" white person, and they believe it's a right limb. It was clean-shaven, suggesting it belonged to a woman. But the Medical Examiner's Office has not officially determined the gender of the victim.
The leg had no tattoos, no distinct marks or scars. There were no other signs of trauma, except for some mysterious marks around the upper thigh. It was dotted with seaweed and other debris when it was found. The condition of the limb suggested it had been in the water for one to two days.
Investigators will first check reports of missing persons, said police spokesman Mike Puetz. But based on what police know so far about the victim, no one matching that description has been reported missing in St. Petersburg.
So investigators are also looking at missing persons' cases in Pinellas, Hillsborough and Manatee counties.
"Normally, we'll ask law enforcement agencies in the area if they have missing persons," Puetz said. "But it'll be more helpful when we get some kind of descriptor — like sex, approximate age, approximate height and weight, race, maybe some issues regarding cause of death — from the Medical Examiner's Office."
Investigators can also use DNA to try to identify the victim, but Puetz pointed out that will only work if that person's genetic profile is already in a law enforcement database.
Officers on land and water searched the city's shoreline Tuesday for more body parts and will keep searching in the coming days. Meanwhile, police are asking the public to contact them with any information that could help them identify the person whose leg washed ashore. There's no shortage of ways for a leg to be dumped into Tampa Bay, which is home to numerous marinas and boat slips, countless backyard docks and also commercial shipping lanes.