Historical clue formulations

• – — 2025-04-24
• Genre of the Edgar Awards — 2020-01-06
• What often comes with a twist? — 2013-07-20
• Open case — 2005-12-18
• Head-scratcher — 2003-12-07
• See 52-Across — 2003-11-21
• Whodunit — 2002-01-21
• Agatha Christie genre — 1996-04-30