I believe Holmes may have replaced his own body in an insurance scam
But seriously, Its more likely that it ended up an exhibit in a freak show.
No, that was the body of one David E. George, a drink addled drug addict who died in Enid, Oklahoma, a suicide, in 1903, but who (supposedly) confessed on his death bed he was really John Wilkes Booth. A lawyer named Finis Bates had the corpse embalmed and exhibited it around the country as Booth's corpse. At one point Henry Ford showed an interest in purchasing this macabre exhibit for Dearborn Village, but was talked out of it.