1) Trying to collect on a check, including by either sending it to collections or selling the debt to a collections agency, has no effect on criminal liabilty. If you committed a criminal act, you could potentially be prosecuted regardless of whether and how anyone tries to collect.2) If you wrote bad checks knowing the account was closed or that there were insufficient funds, you committed  a crime. That knowledge--that the check would not be honored--is what makes it criminal.3) How long a merchant has to pursue the matter depends on a number of factors, including the nature of the underlying transaction and the state (not just your state; potentially you could be sued in the merchant's state, too). It's often at least 3, potentially 6, years, but both longer and shorter periods are not unheard of. You'd need to consult with an attorney about specific cases or instances for an answer.