A trial is set to begin for two East Haven police officers charged with violating the rights of Latinos and their advocates. Last year prosecutors charged Dennis Spaulding and David Cari with conspiracy against rights, deprivation of rights, and obstruction of a federal investigation. Spaulding was also charged with using unreasonable force. Testimony in their trial is beginning Monday in US District Court in Hartford. They were among four East Haven officers charged; Officer Jason Zullo pleaded guilty to obstruction of justice in October. Sergeant John Miller, former president of the police union, pleaded guilty last year to violating a person’s civil rights by using unreasonable force. Cari retired last year.