According to an audit, 42 entries in the "CalGang" database, a database used by law enforcement agencies across California which supposedly tracks known gang members, are under the age of one!

...28 of these babies are classified as "admitting to being" gang members.

http://www.voiceofsandiego.org/topics/pu...-gang-database/

The only reliable way of confirming membership would be reading tattoos. And even then, some cops get it wrong.
Gang members will lie about their identity all the time, especially if they aren't already in the system and have no record.
Asking other people in the area about a certain individual's affiliation should also be considered unreliable.
Then the problem of level of activity. Being a a non active gang member vs being active.

The McCarthyan black list is bad enough. I personally know some gang members that just stopped banging. This notion that once someone is a gang member, they're in it for life, is just b.s. Most of them just get old. They just become parents and grandparents. Many of them start to rely on their kids and their employment because they're unemployable. The concept of the CalGang file was shady as hell to begin with, it was a tool to brand people for life and punish them in case the courts didn't. Then to think they're putting infants on this file? They're taking infant children of gang members and getting them on the file as soon as possible? Deja Vu all over again for law enforcement in California. Indictments on the way. I hope the LA Sheriffs weren't involved in this. Another scandal would just about bury them.