SAN DIEGO -- Key evidence was placed before a jury Thursday in the trial of a San Diego County Sheriff's deputy accused of having ties to the Mexican Mafia.

Deputy Andres Villota is charged with one felony count of a peace officer filing a false report, two misdemeanor charges of destroying or concealing evidence and one more misdemeanor of unauthorized possession of a hypodermic needle.

The evidence presented was a box with tennis shoes filled with narcotics that Villota found in the jail. Villota said he turned it in and he had no suspect. The prosecutor in the case said Villota knew of a suspect but failed to report it, and that was his crime.

Sgt. Stefan Kopchak, a detention sergeant for the Sheriff's Department testified that drugs are routinely found at the jail.

"It's a very minor incident; rarely results in identification of suspect. It's found in a common area and generally can't be linked to anybody, but it is documented," said Kopchak.

Kopchak said the quantity of drugs was very unusual -- more than 5 grams of methamphetamine and more than 23 grams of heroin.

Julio Contreras, a prison inmate at Tehachapi State Prison with ties to the Mexican Mafia, was brought in Thursday to discuss who was at county jail when the box of drugs was discovered. Contreras was granted immunity for his testimony, but refused to answer any questions.

"With all due respect, I don't want to waste you guys' time or anything, but I got nothing to say to you guys," said Contreras.

Judge William Kronberger Jr. held Contreras in contempt of court and sent him back to prison.

Before leaving, Contreras requested a copy of his testimony to show his friends that he did not cooperate with authorities.

The district attorney targeted Villota because an informant pointed to him as someone working with the Mexican Mafia. An FBI attempt to catch him accepting a $100 bribe failed when he refused the money. The informant was labeled untrustworthy by an undercover officer called to the stand on Thursday.

Villota's attorney admitted his client did minor favors in hopes of becoming a better officer by gaining prisoners' trust. Villota's attorney insisted he did commit any criminal acts.

The trial continues Friday and is expected to go to the jury next week.

The defense attorney said no decision had yet been made whether Villota will testify.

If convicted, he faces nearly four years in prison.