"There are at least 18 gangs within the Los Angeles County Sheriff's Department," according to the investigation, and they are allegedly tied to the deaths of at least 19 people, all of whom were men of color. Castle's reporting includes a database of names of deputies reportedly involved in these gangs. The department did not speak to the journalism outlet for the series.

This week, the civilian oversight board charged with keeping tabs on the Los Angeles County Sheriff's Department (LASD) announced it's launching an investigation into the prevalence of deputy gangs within the department.

The investigation is set to take five to six months to complete.TIn a letter sent to Villanueva, LA County Inspector General Max Huntsman demanded documents from the department that are still owed to investigators.