This bookkeeper is deaf, an occupational benefit since it was assumed that a deaf bookkeeper would not be able to hear anything he'd ever have to testify about in court.
When the mafioso confronts the bookkeeper about his missing money, he brings along his attorney, who knows sign language. The mafioso asks, "Where's the ten million bucks you embezzled from me?" The attorney, using sign language, asks the bookkeeper, and the bookkeeper signs back. The attorney tells the mafioso, "He says he doesn't know what you're talking about."
The mafioso pulls out a 9-mm pistol, puts it to the bookkeeper's temple, cocks it, and says, "Ask him again!"
The attorney signs, "Don Vito will kill you for sure if you don't tell him!"
The bookkeeper sighs and signs back, "Okay, you win. The money is in a brown briefcase buried behind the shed in my backyard on Staten Island."
The mafioso asks the attorney, " Well, what'd he say?"
The attorney shakes his head. "He says you don't have the guts to pull the trigger."