ALERT: Family dog shot and killed by a sheriff who allegedly let himself into their backyard in San Bernidino, California.Jesus Serna and his family are not living in their home while it is under construction, and occasionally take the dogs over to stay at the house.The San Bernardino Sheriff's Department was investigating a stolen car in the neighborhood when an officer allegedly knocked on the vacant home's door and let himself in.Security footage shows one of the Serna family's dogs, Raven, w