Bob Smith wrote a bad check to ABD Company. At the time that Bob wrote the check, there were no laws against writing a bad check. Ten days later a statute was passed that made writing bad checks a misdemeanor or a felony offense, depending on the amount of the check.

Based on the above information, answer the following:

$$ Can Bob be prosecuted for writing the bad check to ABD Company? Why?

$$ Would your answer change if Bob wrote another bad check after the statute was passed? Why?