Any charge involving the possession and/or distribution of child pornography would be classified as at least a third degree felony depending on the specific circumstances. The statute of limitations for any felony is at least 3 years from the date that the offense was committed. The limitations period may be longer due to one of several exceptions enumerated in the governing statute. You should consult with a lawyer to discuss the difference between the date that the offense was committed and the date the the offense was discovered. You should also discuss with a lawyer any possible defenses that you may have based on whether or not the images were intentionally possession and/or distributed.