Arthur "The Brain" Rachel stole Marlborough Diamond in 1980, going back to prison

(CBS/AP) CHICAGO - Arthur "The Brain" Rachel, a reputed Chicago mobster who first gained notoriety three decades ago for stealing the Marlborough Diamond from a London jewelry store, is going back to prison, this time for racketeering.

A federal judge Thursday sentenced Rachel to 8 1/2 years in prison for his role in several unrelated robberies in recent years. Rachel told the court he and his cohorts were bored and had nothing better to do.

Before the sentencing, Judge Harry Leinenweber had asked the 73-year-old why he got involved in planning more robberies after spending so much of his life in prison.

Rachel and an accomplice staged a daring daytime theft of the 45-carat Marlborough Diamond in 1980. They began serving 15-year prison terms in 1984 and were released in 1993.

The diamond was never recovered.