LOS ANGELES (Reuters) - Former Los Angeles County Sheriff Lee Baca was convicted on Wednesday on federal charges stemming from what prosecutors said was an attempt to thwart a federal investigation into corruption at his department.

Baca, 74, was convicted on one count each of obstruction of justice, conspiracy to obstruct justice and lying to federal agents, Federal Bureau of Investigation spokeswoman Laura Eimiller said.

He faces a maximum sentence of 20 years in prison, although federal sentencing guidelines typically call for less time.

The verdicts came in the Baca's second trial on the charges. A mistrial was declared in the first trial in December after a jury deadlocked.

Baca pleaded guilty in February 2016 to one count of lying to federal investigators, but withdrew that plea six months later after a federal judge ruled that the six-month prison term prosecutors recommended as part of the plea agreement was too lenient.

The case stems from a wide-ranging federal investigation of inmate abuse by sheriff's deputies and other wrongdoing, including cover-up attempts, at two downtown Los Angeles jails.

Baca retired in 2014 in the midst of the corruption probe, which has led to 17 convictions.

His attorneys contended that Baca was unaware of efforts inside his department to impede the investigation, and that his former second-in-command, Paul Tanaka, was to blame.

Baca's lawyers also say he is suffering from the early stages of Alzheimer's disease.

Tanaka is currently serving a five-year sentence for his role in the case.

(Reporting by Dan Whitcomb; Editing by Alistair Bell and Grant McCool)