It was a very cold case.
On the night of July 17, 1918, the last Russian Czar, Nicholas II, and his wife and five children were shot by Bolshevik executioners at the dawn of Soviet rule.
The challenge for the last 90 years has been proving it.
Since then, rumors that one or more of the Romanov children had escaped have spread like wildfire, forever fanned by people claiming to be survivors.
Anthony Falsetti, a UF anthropology professor, has been a lead investigator in the royal family's mysterious demise for years.
Because of his work, Falsetti will be featured in a National Geographic Channel investigation titled "Explorer: Finding Anastasia," which premieres tonight at 10 p.m.
Falsetti was involved in the analysis of the first Romanov remains found in 1991, which used DNA testing to identify five members of the royal family. The remains of two of the children, Alexei and either Maria or Anastasia, were still missing.
In fall 2007, more remains were discovered about 70 yards from those found in 1991.
Falsetti said it's possible there was not enough room in the first grave, so they were buried in the closest space trees and roots would allow.
Falsetti was recruited by National Geographic to analyze DNA from 44 bone fragments to determine if the remains belonged to the missing children.
Most of the work was funded by a grant from the National Geographic Society, Falsetti said.
He and his colleagues sent the children's DNA samples back to the U.S. and compared them with the parents' DNA. Their forensic work confirmed the remains belonged to the missing children.
Though experts disagree on which sister was found with Alexei, the family's only son, all four daughters are now accounted for. The findings were backed up by DNA tests done in Russia and the U.K. as well, Falsetti said.
"Hopefully, this will dispel the rumors that somehow this family escaped," he said. "And certainly Anastasia and Alexei were killed that night."
Falsetti said he later tested bullets and ceramics found at the site and ventured into archives in Moscow, which hold accounts of some of the confessed murderers, to figure out what really happened that night.
He believes most of the mystery stems from the killers' botched clean-up job.
"They hadn't really thought this through," Falsetti said, "and I don't know if this part is true, but there may have been a lot of vodka involved."
Remains belonging to the two children were severely damaged, leading investigators to conclude that the murderers initially wanted to burn all the bodies but gave up when the two bodies failed to ignite.
"After 90 years, the mystery is solved, and the royal family can be buried together," he said.
