Forensic Researcher
Creature — Merfolk Detective
: Untap another target permanent you control.
, Collect evidence 3: Tap target creature you don't control.
Aldo Domínguez
Rulings
If you can't exile enough cards to meet or exceed the required mana value, you can't choose to collect evidence at all.
(wotc • 2024-02-02)
Once you've announced that you're casting a spell, players can't take actions until you've finished doing so. Notably, opponents can't try to remove cards from your graveyard to stop you from collecting evidence.
(wotc • 2024-02-02)
Rulings
If you can't exile enough cards to meet or exceed the required mana value, you can't choose to collect evidence at all.
(wotc • 2024-02-02)
Once you've announced that you're casting a spell, players can't take actions until you've finished doing so. Notably, opponents can't try to remove cards from your graveyard to stop you from collecting evidence.
(wotc • 2024-02-02)