South LA has made great strides when it comes to gang violence over the last several decades, and one tool in the belt of law enforcement has been a database called CalGang. It’s supposed to be a place where law enforcement can cross-check the names of suspects or people in police custody with a list of known gang members. However, according to a state audit out this week, the database is deeply flawed. There are unverified entries, out-of-date information and some of the information is just plain wrong. As it turns out, that can have far-reaching consequences, because immigration officials use the data to deport undocumented people, including those who may have never had gang ties in the US.