An admitted career burglar tied to the Outfit’s Grand Avenue crew has pleaded guilty to a gun crime that could keep him behind bars until he dies, court records show.

Federal prosecutors have recommended Charles Russell — a convicted murderer and rapist  — receive more than 21 years in prison for possessing a firearm as a felon.

Late last year, Russell was let out of jail on electronic monitoring after his lawyer told the court his client is suffering from terminal prostate cancer and wasting away.

Russell arranged to stay in a condo owned by his girlfriend, Patricia Spilotro — a relative of Anthony and Michael Spilotro, the Outfit members whose double murder in 1986 was featured in the movie “Casino.”

Russell, 68, was arrested on Dec. 21, 2016, after he bought eight guns from an undercover agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives. He was plotting to rob a 70-year-old lawyer of $300,000 from a safe, prosecutors said.

Earlier this month, Russell pleaded guilty to illegal possession of a Smith & Wesson .38-caliber revolver that agents found in his home on the day of his arrest.

Russell was secretly recorded talking to the undercover agent about putting torches to his victims’ feet to force them to open their safes. He also said he went to prison in 1973 for killing the “rat bastard” who testified against him.

Russell told the agent he carried out thousands of burglaries over a four-year period. According to prosecutors, he even showed a photo of a car riddled with bullets, then handed the agent an Illinois driver’s license of a black man, saying, “He’s deceased.” The man on the driver’s license was shot in November 2016 and his killing remains unsolved.