The Los Angeles County Sheriff's Department hired dozens of officers even though background investigators found they had committed serious misconduct on or off duty, sheriff's files show.

The department made the hires in 2010 after taking over patrols of parks and government buildings from a little-known L.A. County police force. Officers from that agency were given first shot at new jobs with the Sheriff's Department. Investigators gave them lie detector tests and delved into their employment records and personal lives.

The Los Angeles Times reviewed the officers' internal hiring files, which also contained recorded interviews of the applicants by sheriff's investigators.

Ultimately, about 280 county officers were given jobs, including applicants who had accidentally fired their weapons,  had sex at work and solicited prostitutes, the records show.