Sheriff's officials balked at the size and scope of the subpoenas when they were served several weeks ago and are negotiating with federal prosecutors to reduce the number of documents they must produce.
A source familiar with the demand said it sought the names of everyone who has worked in the jails since 2009, even janitors, and whether they have been disciplined for misconduct. Federal prosecutors also sought employees' Social Security numbers, dates of birth, home addresses, phone numbers and personal email addresses.
FULL COVERAGE: Jails under scrutiny
The records demand is the first sign that federal authorities are not simply looking into several individual cases of jail brutality and other misconduct but are taking a broader look at potential wrongdoing by deputies going back years.
"I was caught completely flabbergasted," Sheriff Lee Baca said of the growing federal scrutiny of his jail system, the nation's largest. "It's like your best friend digs up your favorite rose bed."
In an interview with The Times, Baca said the subpoenaed records were so voluminous that even federal investigators "would have had difficulty ferreting through it all." Nevertheless, Baca said, the county has begun collecting the records.
Federal officials declined to comment about the subpoenas or discuss details of the investigation.
Rebecca Lonergan, a USC law professor and former federal prosecutor, said the demand for the records suggests that investigators are looking for witnesses who would be willing to cooperate as they explore whether there might be a pattern and practice of deputy misconduct in the jails.
"The question becomes whether it rises to a supervisory level," said Lonergan, who handled police misconduct cases while supervising the U.S. attorney's public corruption section in Los Angeles. "If so, it may not be just the individual deputies who are culpable. It may be supervisors all the way up to higher-ups in the Sheriff's Department."
The subpoenas come amid renewed scrutiny over the county's jail system, which has been plagued over the last decade by inmate riots, killings, the formation of a gang-like deputies clique, early release of inmates, antiquated facilities and huge legal settlements. Over the last three years, the county has paid $8.4 million to resolve claims of excessive force and failure to care for inmates, a spokeswoman for Supervisor Gloria Molina said.
Last month, The Times reported that the FBI is investigating allegations of inmate beatings and other deputy misconduct. Among the claims under review are those made by an American Civil Liberties Union jail monitor who said she witnessed deputies knock an inmate unconscious and beat him for two minutes at the Twin Towers jail.
Agents are also investigating allegations that guards at the Men's Central Jail etched letters into the scalp of a black inmate, representing a Spanish-language racial slur. A third case under review involves an inmate who alleged that deputies broke his jaw and several other bones in his face during a beating at the Men's Central Jail.
The ACLU, which is a court-appointed monitor of jailhouse conditions, has produced sworn declarations from inmates and civilians who work in the jail, including two jail chaplains, who said they witnessed deputies deliver beatings.
Public concerns over the allegations gained momentum after The Times reported that an undercover FBI sting had ensnared a deputy who allegedly sneaked a cellphone to an inmate who was a federal informant.
Baca initially criticized the FBI after the undercover sting and defended his department's record in the jails.
In the last week, however, the sheriff struck a more conciliatory tone, saying he would welcome a wide-ranging federal civil rights investigation and acknowledging that some deputies have brutalized inmates.
Earlier this week, the Office of Independent Review, which monitors Sheriff's Department discipline, released a report detailing a dozen cases in which more than 30 jail employees were suspended or fired over the use of excessive force against inmates. The report concluded that other deputies "get away" with misconduct as a result of a code of silence, "lackluster, sometimes slanted and insufficiently thorough" investigations and a lack of physical evidence to support conflicting accounts of what happened.