Don't even think about writing a note to plead not guilty to a serious criminal offense; instead, enter your plea personally in court with an attorney present. Entering a plea of not guilty by letter is only appropriate when you are charged with a minor traffic violation.
Paying a Traffic Ticket
If you get a citation for speeding or some other traffic violation, you are often given the choice of paying the fine or contesting the ticket. Only pay the fine if you do not intend to plead not guilty to the offense. Paying the fine is generally treated by the court and your insurer as the equivalent of a no contest, or nolo contendere, plea, which has the effect of pleading guilty to the offense as charged.
Contesting a Traffic Ticket
If you wish to plead not guilty, read the fine print on the traffic citation. In some states, you plead not guilty on the Internet, by mailing in the citation with the "not guilty" space checked. You can also enter a plea by telephone. In other states, however, you must provide a letter explaining the circumstances that led to the citation. Simply set out the facts as they occurred, put the citation number and your name on the letter, sign the letter and send it in, together with the citation.