The widening scandal at the Los Angeles County Sheriff's Department has at its center a top-secret operation that federal prosecutors said amounted to an outrageous case of obstruction of justice.
Here's a primer on "Operation Pandora's Box" from the Los Angeles Times archives:
What was Operation Pandora's Box?
It was launched after sheriff's officials learned in the summer of 2011 that the FBI had enlisted Anthony Brown, an inmate in the Men's Central Jail, to collect information on allegedly abusive and corrupt deputies.
In an unusual move, sheriff's officials responded by moving the convicted bank robber to a different jail under a fake name.
They assigned at least 13 deputies to watch him around the clock, according to documents reviewed by The Times. And when the operation was over, the deputies received an internal email thanking them for helping "without asking to many questions and prying into the investigation at hand."
Sheriff Lee Baca has said Brown was moved, not to hide him from the FBI, but to protect him from deputies because he was "snitching" on them.
Prosecutors allege the goal was to hide Brown from the FBI.
What was the role of former Undersheriff Paul Tanaka, who was indicted Thursday on corruption charges?
An internal Sheriff's Department email, written while Brown was allegedly being hidden from the FBI, states that Tanaka or one of his subordinates had to be present before deputies could move Brown.
In the email, Deputy Gerard Smith warns his colleagues: "To keep yourself free of any controversy ... let the approved, above listed people deal with Browns issues. ... It has been expressed to me (several times now) that this is one of the most important investigations involving The Los Angeles County Sheriff's Department in its 160 year history. No joke."
Tanaka has said he had a minimal role in the Brown matter and that he did nothing improper or illegal.
What do Thursday's indictments allege?
Prosecutors say Tanaka and former Capt. William "Tom" Carey gave orders to conceal Brown.
"The allegations in this indictment include cover-ups, diversionary tactics, retribution and a culture, which is generally reserved for a Hollywood script," David Bowdich, assistant director in charge of the FBI's Los Angeles field office, said at a news conference Thursday morning. "No one is above the law."
Who is Anthony Brown?
In a 2012 profile and interview with Brown, The Times outlined Brown's role:
He took down the names of sheriff's deputies who he alleged were dirty. He reported tales of violent abuse of inmates at the hands of jailers. He even ensnared a deputy in a phone smuggling scheme that resulted in a criminal conviction.
Brown gave FBI agents what they couldn't have gotten on their own: an insider's view of a jail system beset with allegations of excessive force and other deputy misconduct.
Brown is serving a lengthy prison sentence for bank robbery and has a long criminal history. He was a former crack cocaine addict who has a history of lying and making dubious allegations against law enforcement, according to court records and interviews.
In his interview with The Times, Brown alleges that he delivered notes about corrupt and brutal deputies during weekly visits with his FBI handler.
Brown helped with an undercover FBI operation to bribe a jailer, who smuggled him a cellphone. Brown said he used the phone to take photos of deputy beatings and transmit them to his FBI handler. The Times could not independently verify whether he provided photos to the FBI.