Deputy Billy is the deputy of Hurleyville, New York.
Billy arrested a 16 year old Dean Winchester for trying to steal peanut butter and bread from Steven Hewlett's store. When Dean's father John offers to have Dean "rot in jail", Billy decides to bring Dean to Sonny's for the time being.
However, Dean was highly resistant and sucker-punched Billy, leaving him with a black eye, and forcing Billy to wear sunglasses for a while. Billy handcuffed Dean to dragged him over to Sonny's place, and explained Dean's situation. When he revealed his black eye to Sonny, Dean laughed at him, much to Billy's annoyance. Dean accused Billy of being slow, which earned him that black eye.
When Billy left, Sonny reprimanded Dean for being mean to Billy. Dean was uninterested, until Sonny informed Dean that by upsetting Billy, Billy left Dean handcuffed and took the keys with him.