The term given to an old-style mafia method of murder in which one's feet were cemented and then the person was dropped into a river.

If you try this, be sure you let the cement dry first. The whole point of the large tub of cement is to prevent the corpse from floating when it bloats -- a corpse that isn't properly weighed down will generate a lot of gas as it decomposes, and the gases that get trapped have been known to make the body rise to the surface and incriminate the murderer.