The former sheriff of Los Angeles County has been convicted for his role in a scheme to block an FBI investigation into mistreatment of inmates in his jails.For 15 years, Lee Baca led the nation's largest sheriff's department. He was among the most powerful law enforcement leaders in the country.Part of Baca's job was to oversee the jails, where there were allegations of deputies beating inmates, including those in handcuffs.The FBI started investigating civil rights abuses, but those efforts were blocked in 2011 when the sheriff's department discovered a cellphone the FBI had given an informant.Deputies hid an inmate informant from the FBI. Later, they approached an FBI agent at her house and threatened to arrest her. Prosecutors said Sheriff Baca led the conspiracy.Baca was tried before but the jury couldn't agree on a verdict. This time, a jury found Baca guilty of conspiracy, obstruction of justice and making false statements.The jury foreman told reporters that prosecutors presented their case well and pointed to testimony by a former assistant sheriff who said he warned Baca not to mess with the feds.Federal officials claimed victory and said the decision shows no one is above the law — not even the sheriff.Speaking on the courthouse steps after the verdict, Baca thanked his lawyers and wife, and vowed to press on."You've known me for a long time," Baca said. "I am a faith-based person. My mentality is always optimistic. I look forward to winning on appeal."Baca, 74, has been diagnosed with the early stages of Alzheimer's disease. He faces up to 20 years in federal prison. Copyright 2017 Southern California Public Radio. To see more, visit Southern California Public Radio.