FREDERICK, Md. (AP) — A sixth-grade teacher was sentenced yesterday to nine months in jail plus nine months of home detention for writing threatening notes to five students with messages such as "Tick Tock Tick Tock. Is it a bomb or is it a clock?" Michelle J. Dohm, 42, of Thurmont, did not acknowledge guilt or remorse during the hearing but expressed sympathy to the victims' families. Dohm was convicted by a judge in April after agreeing to a statement of facts that included handwriting analysis and a microscopic comparison of fibers in postage stamps. "She has consistently and emphatically...