Dead man Walking

I have seen on a few occasions (in movies and TV) a guard walking an inmate whom is about to be executed, shout “dead man walking”. Is this true to life? Why do they do that? What is the history?

sounds like a crock to me. Sort of like screaming “Hey, the guy that we’re about to execute is coming! Whooo-hoo! Please, can all of the other inmates start yelling and banging on their cell doors!” I’'m sure that when the goner is enroute, the people that need to know about it already do.
hh

Sister Helen Prejean is said to have used the title for her 1993 book because of the phrase being used at San Quentin.

no, it’s not true. My husband has been on several execution teams, and I can verify that it’s not said, at least in my state.

Nor are inmates about to be executed kept in the general population where anyone can yell at them. Before their execution, they are housed in a special isolated cell on Death Row usually only a few paces from the execution chamber.