 The large number of attacks against women in the East End during this time adds uncertainty to how many victims were killed by the same person . Eleven separate murders , stretching from 3 April 1888 to 13 February 1891 , were included in a London Metropolitan Police Service investigation and were known collectively in the police docket as the " Whitechapel murders " . Opinions vary as to whether these murders should be linked to the same culprit , but five of the eleven Whitechapel murders , known as the " canonical five " , are widely believed to be the work of Jack the Ripper . Most experts point to deep throat slashes , abdominal and genital @-@ area mutilation , removal of internal organs , and progressive facial mutilations as the distinctive features of the Ripper 's modus operandi . The first two cases in the Whitechapel murders file , those of Emma Elizabeth Smith and Martha Tabram , are not included in the canonical five . 
