Possible Clues:

• Silly as transgressions and more dangerous
• Silly, like the transgressions of murderers
• Joyce Carol Oates subjects terminate with extreme prejudice
• Silly like transgressions? Yes, if they're murderous
• Silly as transgressions that lead to 32 across
• Sondheim musical with a quintet
• With fools at the crease, spinners start to become hit men
• Killingly silly as transgressions
• Eventual winner Octave Lapize’s description of the 30A’s organisers as murderers, shouted at them as he led its first ascent of the Col d’Aubisque in 1910
• Some CIA Special Activities Division operatives