What are the implications of "ve'Chol ha'Am Yishm'u Veyira'u"?
Rashi: It implies that Beis-Din are Chayav to announce the impending death of a Zakein Mamrei - 'P'loni and P'loni are being put to death because they became Zom'min in Beis-Din!'.
Refer to 17:13:1:1 & 17:18:1:3? See Sifsei Chachamim.