Jury selection in the for started on Wednesday in a Contra Costa court, reported the San Gabriel Valley Tribune.
According to the newspaper, a judge decided that Concord Police acted with reasonable cause when in March of this year. Hernandez was charged in May.
Mary Ann O'Malley, Contra Costa Superior Court Judge, denied a motion by the defense to suppress evidence arguing that the legislator was not driving, and that he did not behave in a way that would justify detention by police and DUI charges, informed the Tribune.
Hernandez was arrested under suspicion of driving under the influence of alcohol. , saying at the time that he had only consumed a couple of glasses of wine.
According to the Tribune, Agent Mike Roberts testified on Wednesday that he detained the assemblymember after observing him change lanes without signaling, and that he detected a "strong smell of alcohol" coming from the vehicle.
The agents also said that Hernández failed three sobriety tests in the parking lot of the hotel where he was detained, and that his "walking was unstable".
The trial is expected to last until at least August 17.