Hundreds of letters claimed to have been written by the killer himself, and three of these in particular are prominent: the "Dear Boss" letter, the "Saucy Jacky" postcard and the "From Hell" letter.
Ratusan surat diklaim telah ditulis oleh sang pembunuh sendiri; tiga di antaranya yang paling terkenal adalah surat "Dear Boss", Kartu pos "Saucy Jacky" dan surat "From Hell".