Whodunit? Investigate leads from the clues (5)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

A somewhat unusual clue, but logical enough. The initial letters (leads) of the clues in this puzzle (across and then down) are an acrostic, spelling out GREEN IN THE DINING ROOM WITH THE THIRTY-ONE A. Replace “thirty-one A” with the solution to 31a DAGGER, and you have a possible resolution to our theme game Cluedo (Clue). So the killer is Reverend Green (or Mr Green or Mayor Green, depending on your version of the game).