A smart gang officer will talk with gang and non-gang inmates. Since the non-gang inmates are often the victims of the gangs and other security threat groups, they commonly will cooperate with staff against the gangs, if their safety can be guaranteed.
Gang intelligence cards, photographs, and gang data taken during custody for computer intelligence files, tend to be more reliable than data generated by a street gang unit. This is often due to the ability of the custody officer to interview the "captive audience" at length without interruption, as opposed to the difficult circumstances often encountered by field gang officers.
If you are a law enforcement administrator, consider multiplying your gang intelligence resources with a gang liaison officer or gang unit in the jail. If you are a gang officer working on the street, consider cultivating an in-custody officer to assist you in the jail. Invite him or her to participate in sweeps and when you serve warrants. This will fire up the sometimes dull routine these officers must often endure, and encourage the exchange of information.
It is common in the custody environment to conduct detailed body and cell searches. This developed skill can be useful when serving search warrants in the field. In my experience, these jail-trained officers often find contraband missed by patrol officers.
There is one final benefit to the use of jail officers to develop gang intelligence. Many of these officers will eventually wind up as patrol officers in the streets. They will have a significant advantage over other new patrol officers because of this experience.