After a certain time period (arbitrarily designated by the government
under which you live), you can no longer be prosecuted
for a crime. For instance, if someone starts looking through archived security tapes and notices that you shoplifted
something twenty years ago, the statute of limitations prevents you from being brought to trial.
In the USA
, statutes of limitations are set by the individual states. Most high-order felonies
like first-degree murder
, or kidnapping
don't have statutes of limitations, and other crimes like fraud
have statutes of limitations of around 3 years.