This is an old Irish legend and ritual.
Theft was not taken lightly in Ireland, and the Irish people had a ritual in order to classify these criminals as thieves and make known to others that the crime they committed was indeed theft.
The legend goes that, if someone convicted of theft died, as they were buried and put into a coffin, the diener, the person who handles the body, would raise the person’s right arm up. This would let everybody else know that the man or woman was a thief and lived a life of crime.
The informant who told me this story is a long-time family friend of mine (she is a friend of my mother’s and I have been close with her children for most of my life). Her heritage stems from Irish culture, and she was told this legend by her mother. Her mother was born in Ireland and knows much about Irish folklore, and through many stories about her heritage, the informant has kept them in her mind for many years, for learning about ones past and background is something one does not forget. It is interesting that such a small-scale ritual has been passed down through their family. She loves everything regarding her culture, and it is no different in this context. She did admit that the legend is somewhat invasive and creepy, but it was from old Ireland, and back then customs were very different compared to today’s world.
I found this legend surprising. I am Irish as well, but I have never heard of anything like the legend I was told, but it nevertheless fascinated me. Theft was such a big deal that, when deceased, the dead would be branded as a thief even after his death, and upon hearing the legend made me realize that the Irish were not to be stolen from. The process is in fact creepy and invasive, but I realized that it was due to the pride that the Irish hold over living a life free of crime and full of drinking.