Brown, 37, was convicted on March 6 of two counts of second-degree commercial burglary and one count of receiving stolen property for stealing two computers and three flash drives from the AHMC Healthcare in Alhambra. Personal, financial and credit information from 729,000 patients was compromised.
Brown escaped from the Inmate Reception Center Release area at about 10 p.m. Wednesday.
Sheriff's officials think Brown impersonated another inmate who was scheduled to be released. Later in the night, a head count revealed he was missing. A search of the jail ensued, and a review of closed-circuit TV showed Brown escaping.
"As a result of the inmate's actions, and that it appears that mandated security practices may not have been followed, the inmate was able to escape through the jail Inmate Reception Center release area door," said sheriff's Captain Mike Parker. "Identified security concerns were immediately remedied."
Brown is a transient with no known address. He has multiple prior theft-related arrests.
He was described as an African-American man about 6 feet 3 inches tall, weighing 200 pounds. The public is advised to contact the L.A. County Sheriff's Department if Brown is seen.