In 2010, the department hired 280 officers from the Office of Public Safety, a Los Angeles County police force that was being dissolved to save money. Most of the hires became sworn sheriff's deputies; others took lower-level positions such as security guards.
Background investigators who checked out the applicants found evidence of dishonesty for nearly 100 people who eventually became part of the department, the Los Angeles Times reported. Not all of the allegations had been proven, and not all were work related.
In all, 29 new officers either had been fired or pressured to resign from other law enforcement agencies.
The sheriff's department is the nation's largest. It has been under fire for alleged abuse of inmates by deputies, among other claims.
The newspaper's report was based on internal files and follow-up interviews. The files included information from sources such as past employers and romantic partners.
Some of the hires disputed what their files said. Others said the incidents happened years ago and did not reflect their current qualifications.
Sheriff Lee Baca did not comment on the specific findings; a department spokesman said Baca was unaware that new hires had troubled backgrounds.
In the past, Baca told reporters for the newspaper that there is no room in law enforcement for people with records of violence or dishonesty, and that applicants fired from other agencies should not receive a second chance.
The department has said it would review whether some of the hires were improper. It also launched a criminal probe to try to find who leaked the files. The union representing deputies unsuccessfully asked a court to block publication of information from the files.
In hiring officers with histories of misconduct, the department risks undermining its integrity, one former sheriff's department commander said.
"Cops are held to a higher standard than the average member of society because we've got to be able to trust them," said Edward Rogner, who was involved in expanding the force with new hires the Office of Public Safety, though not in individual hiring decisions.
Department guidelines give wide latitude in hiring, the paper reported. One person involved in the 2010 round of hiring — Larry Waldie, who is now retired but at the time was Baca's second-in-command — cited "significant pressure" from the county Board of Supervisors and other officials to give the county officers new jobs.
"We had to have grave reasons for not hiring them," Waldie told the newspaper.