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.
Hundredvis af brevene hævdede at være skrevet af moderen selv, og tre af disse udskiller sig særligt: "Dear Boss"-brevet, "Saucy Jacky"-postkortet og "From Hell"-brevet.