Outlaw John Dillinger was wanted for numerous bank robberies and the murders of 10 men when he was killed by federal agents on July 22, 1934. Now, his relatives want to make sure the body in his grave is really his.

The body of infamous Depression-era outlaw John Dillinger — or, at least, the body of whoever is buried in Dillinger's Indianapolis cemetery plot — is going to be exhumed, DNA-tested and reinterred on Sept. 16, cbsnews.com reported.

This grim reaping could finally smother the flames of a conspiracy theory that's been smoldering since the gangster was reportedly shot and killed by FBI agents outside the Biograph Theater in Chicago 85 years ago: Is Dillinger really buried in that grave, or did the feds kill an innocent man? [The 6 Most Gruesome Grave Robberies]

Apparently, Dillinger's family is in favor of the latter hypothesis. Two of his living relatives (his niece and nephew) have filed separate requests to exhume the body after being presented with "evidence" that the corpse in Dillinger's plot may belong to someone else, NPR wrote. That would mean Dillinger was not, in fact, shot and killed in Chicago on July 22, 1934, but lived on and evaded justice for some unknown amount of time in some unknown place. According to Dillinger’s nephew, verifying the true identity of the man in the grave is the first step to answering those unknowns.

In affidavits obtained by NPR, Dillinger's niece and nephew claim that the body interred in Dillinger's grave has several traits that do not match descriptions of their uncle, including eye color, "ear shape," fingerprints and tooth alignment. The only way to clear up the identity of the man in the grave is to dig up the body and perform DNA testing, the relatives wrote, "possibly removing a bone or bones" from the body.

The Indiana State Department of Health approved the request for a Sept. 16 exhumation, with the body scheduled to be reinterred on the same day, CBS reported. The procedure will be filmed as part of a documentary on Dillinger, a spokesperson from the History channel told CBS.

Removing Dillinger's remains could prove trickier than most exhumations, as his casket is reportedly buried under 3 feet (0.9 meters) of concrete slabs and scrap metal — likely placed there by family in 1934 to protect the infamous outlaw's body from vandals and grave robbers.

"The main fear was that someone would come in and dig up the grave and either desecrate the corpse or steal it," Susan Sutton, a historian with the Indiana Historical Society, told CBS News. "The Dillingers had actually been offered money to 'lend out' his body for exhibits, so they were concerned."

John Dillinger earned national fame in 1933 and 1934 after performing a string of violent heists, bank robberies and jailbreaks that netted his crew an estimated $300,000 in stolen cash and left 10 people dead, according to the FBI. Many Americans considered the daring outlaw a hero at the time, and his legend has since gone on to inspire more than a dozen films and TV shows.

Dillinger's popularity did not save him from being shot to death by federal agents when he reached for a gun during an arrest attempt outside a Chicago theater (according to the official history, anyway). The FBI said there is no disputing that the man killed outside of the Biograph Theater was Dillinger.

"A wealth of information supports Dillinger's demise," an FBI page of the top 10 Dillinger myths reads. "Special Agents M. Chaffetz and Earle Richmond, for example, took two sets of fingerprints from the body outside the Biograph Theater, and both were a positive match. Another set taken during the autopsy were also a match."

Are the feds telling the truth, or did America’s public enemy number one live to die another day? We may find out on Sept. 16.

Originally published on Live Science.