Once, the fact that bodies did not decay, and remained sweet-smelling, was a sign that a person is holy according to early Christianity. But today,
it takes a little more work. (Story by the New York Post).
A quote:
When Pope Pius XII died in 1958, the Vatican used a wrapping
technique similar to what was believed to have been applied to Jesus. It failed
miserably. Only days after his death, his nose fell off, and a Swiss Guard
fainted due to the stench while he was guarding the body.
Thanks for the link, AW!
For more information on how dead folks were "proven" to be holy via autopsy, check out the work of Bradford Bouley.