The Night They Shot Santa Claus - S4.E1

December 24, 1930. That evening, small-time mug Hap Levinson is playing Santa Claus at the Sackman Orphan Home. Santa brings toys and ice cream to all the waifs. He walks outside, waves good-bye, and is promptly machine-gunned to death by hoods in a speeding car. Quite a shock for all the kiddies.

Killing Santa is not a federal crime, but Eliot Ness investigates. Hap was a friend of Ness' for 10 years; they had sort of a truce. If Ness was on official business, they were on opposite sides of the law; unofficially, they were pals.