The origin of the death tax was ancient Rome. Nero needed a way to find rebuilding Rome so he levied a death tax. Then nobles across the empire started to die.
For a more recent example, Donald Scott in california had land the government coveted. They were sure that he was growing dope on that prime real estate. So prime that they had the property appraised before they raided the place. He was shot dead and his widow had to sell to the .gov to settle the estate.
Thanks for bringing it up.