OAKLAND -- An Oakland police officer was arraigned Thursday on multiple counts of misdemeanor interference with civil rights and false imprisonment for allegedly making illegal vehicle stops on Asian women.

Richard Valerga, 51, didn't attend his brief hearing in Alameda County Superior Court because his presence was not required to face misdemeanor charges.

The next hearing in the case will be on Oct. 13, when a preliminary hearing date is to be set.

Valerga was charged two weeks ago following a joint three-month investigation by the Oakland Police Department and the Alameda County district attorney's office.

Investigators determined that Valerga made illegal vehicle stops on Asian women between January and April.

During the course of the investigation, it was determined that most of the women recently immigrated to the United States and were illegally detained by Valerga, according to Oakland police.

Deputy Police Chief Michael Holland said two weeks ago that there were multiple alleged victims but declined to be specific, except to say there were fewer than 10. However, the investigation is ongoing and it's possible that more victims could come forward, Holland said.

Holland said Valerga was placed on paid administrative leave in May when allegations were first brought to the attention of the department's command staff.

Valerga will remain on administrative leave for the duration of the criminal case against him and an internal administrative investigation being conducted by Oakland police, Holland said.

Valerga is charged with five counts of interference of civil rights and two counts of false imprisonment.

The officer has been a member of the Oakland Police Department for six years and had been working in the patrol division since 1999.

According to his attorney, Paul Brennan, Valerga began his career as a police officer at a late age because he previously had a long career with the U.S. Navy.