When a charge is statute barred, it means that a defendant can not be prosecuted after a specific period of time as dictated by the particular law. This type of defence has various considerations, such as the time limit or the length of time that can be allowed to pass from the time the offence was committed to the time of filing a case.
Summary offences typically carry a time limit of one year. Some cases of sexual offences also have time limits. Whenever a charge involves historic sex allegations, it is crucial to check with a lawyer if the offence has a time limit; and if so, whether the charge falls within or outside that time limit. The charge will be considered as statute barred only if it falls outside its time limit.
These defences are aimed at fairness. There is (or was, as in sex cases) a belief that after a certain period of time it was not fair to prosecute someone. The accused is disadvantaged in cases that are old by the inability to defend their case properly. This is because of no longer having the opportunity to establish alibis or to show that the defendant did not commit the offences. Often an innocent person has no recollection of an incident because they had no reason to remember details of it.
The defence that charges are statute barred is a very technical defence and must be thoroughly considered when the details of a case involve dates.
This is something that you should raise with your lawyer if you have any questions about the possibility that the charges are statute barred.