By William CrumStaff writerwcrum@oklahoman.comA western Oklahoma sheriff says agreeing to email public records to citizens could set a precedent that could negatively affect his office.As part of a graduate-level project last year, a Marquette University professor asked the Custer County Sheriff's Office for some police reports.Sheriff Kenneth Tidwell made the records available but declined to email them.They could instead be picked up at the office in Arapaho, Oklahoma, near Clinton, he said.That was a problem for A.