DANBURY — A city man was arrested Friday on a warrant accusing him of sexually assaulting an 8-year-old girl, police said. Germano Vilela 41, of Moss Avenue, was charged with risk of injury to a minor, a felony, and fourth-degree sexual assault. Police said the investigation began in 2015, but it did not release further details. Vilela was arraigned in state Superior Court and was released after posting $25,000 bond.