CI
Confidential Informant; Any individual under the direction of a police officer who furnishes information about criminal activity with or without compensation; works under direction of the department; different from other concerned citizens or complainants not working under department direction and not party to the investigation itself.
Example:
My CI places you and your homies at the Quickie Mart last night when the shootings occured.
My CI places you and your homies at the Quickie Mart last night when the shootings occured.