In any prosecution for bail jumping or failing to respond to an appearance ticket, it is an affirmative defense that:

1. 1. The defendant's failure to appear on the required date or within thirty days thereafter was unavoidable and due to circumstances beyond his control; and

2. 2. During the period extending from the expiration of the thirty day period to the commencement of the action, the defendant either:

   1. (a) appeared voluntarily as soon as he was able to do so, or
   2. (b) although he did not so appear, such failure of appearance was unavoidable and due to circumstances beyond his control.