SAN DIEGO -- A mistrial was declared Friday in the case of a San Diego County sheriff's deputy accused of using his job to help members of the Mexican Mafia.

A jury deadlocked on a felony charge of making a false statement in a report and a misdemeanor charge of destroying or concealing evidence against Andres Villota.

The defendant was also acquitted of a separate misdemeanor charge of destruction of evidence.

It was unclear whether prosecutors will seek to retry Villota on the counts on which the jury deadlocked.

Defense attorney Ward Clay said Villota will plead guilty Monday to a charge of unlawful possession of a syringe, which was found during a search of his residence.

Villota testified that he filed a less-than-complete report about finding a box with tennis shoes and a large amount of drugs at the jail.

The defendant said he turned the box in, but did not name any suspects and did his own investigation on the eighth floor of the jail, where several members of the Mexican Mafia were being held.

Villota said everyone questioned about the box denied it.

Prosecutors built their case against Villota on the word of a confidential informant who wore a body wire to gain evidence against the Mexican Mafia, resulting in a major operation last year.

Andrea Gomez said she offered Villota $100 for favors, but he declined. Authorities said Villota never reported the attempted bribe.

Clay admitted that Villota did small favors for inmates, but said it was to win their trust and maintain order in the jail.

Villota could have faced almost four years in prison if convicted of the felony charge.