I have found that James M. McPherson, a noted civil war historian and writer, documents Frederick Douglass' prior knowledge of John Brown's Raid on Harpers Ferry in his book "Battle Cry of Freedom", page 205. Of course McPherson's purpose is not to condeam Douglass with this information.

If this is the case in todays legal system Douglass could be tried as a co-conspirator even thought he advised against the raid to Brown. If found guilty Douglass could have been hanged as Brown was. Failing to inform the authorities once he became aware of Brown's treason and planned attack on Harpers Ferry in todays anti-terrorism atmosphere would make Douglass that co-conspirator. I believe that it would have been the same in 1859 had that been generally known at that time.