Sweet is charged with one count of injury to public records, as well as second degree theft and third degree theft.
Prosecutors also filed alternative stolen property charges if the theft charges don't stick.
Investigators say the former Selah city supervisor stole a laptop computer and hard drive owned by Selah.
Sweet's also accused of illegally deleting and moving public documents.
His attorney will try to get the case thrown out of court.
"At or around the time of the arraignment, we will be filling the motion to dismiss, which will have conclusive evidence that shows that Frank Sweet didn't steal anything," said Attorney Tyler Firkins.
Sunnyside City Council gave Sweet a vote of confidence by keeping him on the job as interim city manager.