(a) Except in unusual cases where the interests of justice would best be served if the person is granted probation, probation shall not be granted to any person convicted of a crime of theft of an amount exceeding one hundred thousand dollars ($100,000).
(b) The fact that the theft was of an amount exceeding one hundred thousand dollars ($100,000) shall be alleged in the accusatory pleading, and either admitted by the defendant in open court, or found to be true by the jury trying the issue of guilt or by the court where guilt is established by plea of guilty or nolo contendere or by trial by the court sitting without a jury.
(c) When probation is granted, the court shall specify on the record and shall enter on the minutes the circumstances indicating that the interests of justice would best be served by such a disposition.