Mob Ledger

Files on the American underworld

Glossary entry

Rat

RAT

Definition

RAT

An informer. A member or associate who gives information to law enforcement, whether under a cooperation agreement or otherwise.

“Once he was named as a rat in open court there was no arrangement that could have kept him alive outside protection.”

Being identified as an informer was the one condition from which no seniority or earning record offered protection. It was also, from the 1970s onward, the single most effective tool the government had.

The turn from Joseph Valachi in 1963 to Salvatore Gravano's testimony against John Gotti in 1992 is the story of that shift: from one frightened soldier who broke under a murder charge to an underboss trading nineteen killings for five years and a new name.

See also

Related terms