Definitions by LostGunMan

5K1 

Also 5-K-1. Refers to someone who provides assistance in the investigation or prosecution of another, used in context to release them from otherrwise mandatory sentencing guidelines.

Related to the 2001 Federal Sentencing Guidelines Section 5.K.1.1

In the Geto Boys song G-Code: "Fuck a 5K1, check his P-S-I"

5K1 by LostGunMan December 26, 2006