Scalp

Scalp was a slang expression arising in the Mid-west encampments created by President Joe Steele in the 1930s. It referred to new prisoners, due to their having their heads shaved or "scalped" when they first arrived at an encampment but expanded to mean any inmate. While an encampment expression, it did spread out to the general population such that when Sgt. Mike Sullivan used it with his subordinates in 1946, they had no trouble understanding him.