Repeat Offender is a common Creature — Human Assassin card from Murders at Karlov Manor (MKM), collector number 101. Current market price: $0.08 (foil $0.11), TCGplayer market prices via Scryfall.
{2}{B}: If this creature is suspected, put a +1/+1 counter on it. Otherwise, suspect it. (A suspected creature has menace and can't block.)