( IDAHO FALLS , ID ) – The Bonneville County Sheriff’s Office is warning citizens about recent mail thefts. They say checks from outgoing mail are being taken from mail boxes. A similar warning was released by Pocatello authorities last week. Officials advise residents to take their checks to a U.S.P.S drop box location instead. Investigators say the thieves are taking uncashed checks, washing them with chemicals, then writing in their own names with the desired amounts.