State Police have arrested a Worcester man in the killing of Vanessa Marcotte, a jogger whose body was found last August in Princeton, according to an official with knowledge of the investigation. Police arrested Angelo Colon-Ortiz early Saturday morning, according to the official. He is being held at the Millbury State Police barracks on $1 million cash bail. Assault charges were filed, said Worcester County District Attorney Joseph Early. “I anticipate there will be a murder charge,” he said. “We’re very comfortable that we’ve got Vanessa Marcotte’s killer,” Early said.