Columbine documents still missing

DENVER -- Authorities decided soon after the Columbine High School massacre to withhold a document showing deputies knew one of the killers had been accused two years earlier of making death threats and building pipe bombs, according to a grand jury report released Thursday.

The grand jury also said it was "troubled" by still-missing documents in what remains the deadliest school attack in U.S. history. But it did not hand up any indictments.