
Whenever you cast an instant or sorcery spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Trail of Evidence has 2 printings, first in Shadows over Innistrad (2016). EDHREC ranks it #9,486 among Commander cards. It appears most in Galazeth Prismari decks (2,904 on EDHREC). It has 3 official rulings.
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.