Historical clue formulations

• School copier, maybe — 2018-09-14
• Test taker going "Psst!," say — 2014-10-13
• One using a crib — 2008-02-16
• One peeking at answers on a test — 2004-10-11
• Crook — 1998-03-21
• Con man — 1993-12-25