During the summer and autumn months of 1888, a series of murders occurred in a small, square mile area of London's impoverished East End quarter of Whitechapel (Evans & Skinner, 2002a, pg 2; Sugden, 2002, pg 1; Canter, 2003, pg 90); these murders, each one involving mutilations of the 'most horrible' description (Daily Telegraph, 10/11/1888, I) provoked an immediate 'state of panic' in the city (The Hackney Standard, 06/10/1888, I) and quickly acquired a farther reaching, grim notoriety across the world (Begg et al, 1994, pg 1). The victims of these so called 'Whitechapel Murders' (East End News, 11/09/1888, I), all casual, street prostitutes (Evans & Skinner, 2002a, pg 2), or 'unfortunates', as the East London Advertiser (08/09/1888, I) described them, totalled five in number (see Table 1), and were widely believed to have fallen to the same killer (Macnaghten, 1894, pg 2); this killer evaded capture by the City and Metropolitan Police authorities of his (or her) day (Evans & Skinner, 2002a, pg 2) and was, accordingly, known only by the sordid soubriquet of 'Jack the Ripper' (Port Philip Herald, 09/03/1891, I). An astonishingly widespread and spirited culture of popular interest in Jack the Ripper and his heinous crimes exists today (Sugden, 2002, pg xi) and they have provided the inspiration for a lavish swirl of novels, short stories, poems, plays, films, musicals and operas (Strachan, 1999, pg ix; Perry Curtis, 2001, pg 1; Begg, 2003, pg ix). In addition to works of fiction such as these, an abundant collection of individuals, aptly referred to as 'Ripperologists' (Kelly & Sharp, 1995, pg 123), have undertaken more characteristically fact based, pragmatic enquiries into the Ripper crimes in an attempt to unmask the true identity of their perpetrator (Whitehead & Rivett, 2001, pg 10); the suspects posited, amongst them an escaped orang-utan, a midwife, a Portuguese sailor, a czarist agent, and a mad doctor (Kelly & Sharp, 1995, pgs 11,12,31), to name but a few, have been many and varied, yet most have been granted little credence (Palmer, 1995, pg ix). However, the latest offering to the altar of Ripperology, Patricia Cornwell's Portrait of a Killer (2002), which takes its lead from Jean Overton Fuller's Sickert and the Ripper Crimes (2001) in outlining the British post impressionist artist Walter Sickert (1860-1942) as Jack the Ripper, has been dismissed less easily (Walker, 2002, I). Cornwell mounted the most expensive private investigation in history (The Independent, 26/10/2002, I), spending over $6 million of her own fortune on her study (Linder et al, 2003, viii), to conduct a vast 'battery of forensic tests' (The Guardian, 08/12/2001, I), the like of which have never been employed in any erstwhile Ripper enquiry (Cornwell, 2002, pg 13). Cornwell triumphantly proclaimed that the evidence unearthed had closed the case, once and for all (Ibid, 2002, frontispiece). In the limited space available, this paper takes a closer look at her work, and attempts to answer the question that has been upon everybody's lips; is the case really closed?
Table 1 (Source; Harrison, 1993, pg xiv; Macnaghten, 1894, pgs 2,3)
|Name||Date of Murder in 1888||Location||Injuries/ Mutilations|
|Mary Ann Nichols||Friday, 31 August||Buck's Row, now Durward Street||Throat cut, disembowelled|
|Annie Chapman||Saturday, 8 September||29 Hanbury Street||Throat cut, disembowelled|
|Elizabeth Stride||Sunday, 30 September||Dutfield's yard, Berner Street, now Henriques Street||Throat cut|
|Catharine Eddowes||Sunday, 30 September||Mitre Square||Throat cut, disembowelled, face slashed|
|Mary Jane Kelly||Friday, 9 November||13 Miller's Court, off Dorset Street||Throat cut, disembowelled, entire body slashed|
Jack the Ripper's DNA and Fingerprints
In her investigation, Cornwell sought to employ the most potent weapon of the modern forensic arsenal, DNA testing, to accumulate evidence against Walter Sickert and reveal him as Jack the Ripper; her team of forensic scientists took over 52 samples from the paper surfaces, envelope flaps and stamps of the letters which had, allegedly, been sent to various authorities and individuals of the day by the Ripper himself, and from those that Walter Sickert had sent to his friends and family (Cornwell, 2002, pg 206). No nuclear DNA was found in any of these 52 samples during the first round of tests, and similarly, the second round of testing proved equally as fruitless (Ibid, 2002, pg 207). Still undismayed, Cornwell commissioned yet another, third round of testing, this time, for mitochondrial DNA (mtDNA) ; the results yielded only one single donor mtDNA profile from a Ripper letter sent to Dr. Openshaw of the London Hospital Museum, which was specific enough to eliminate 99 per cent of the population as the person who wrote it, although the very same single donor genetic markers of this sequence were also found in two mixed donor mtDNA profiles from Sickert letters (Cornwell, 2002, pgs 15, 212). This led Cornwell to believe that she had unearthed a DNA 'match' which aligned the forensic 'compass needle' directly with Sickert (Medine, 2004, I), and 'clinched the case against him' (The Independent, 26/10/2002, I). However, a series of stubborn problems would have to be overcome before any such 'match' could be accepted and Cornwell's premise granted any reverence.
The first substantial difficulty lies in establishing with a compelling degree of certainty that the mtDNA markers found on the mixed donor Sickert letters were those of Sickert himself. Since they were written, the letters have been handled innumerable times by their recipients, archivists and researchers, many of whom have left their own mtDNA markers on the letters (Ryder, 2004, I). The most reliable way that it could be ascertained which of these countless mtDNA markers, if any, were those of Sickert's, would be to find DNA that was conclusively known to emanate directly from his person, yet Sickert was cremated after death rendering the exhumation of his body for such DNA impossible (Yeh, 2003, I). The only other feasible means of establishing if any of the mtDNA markers on the letters were Sickert's would be to examine the mtDNA profiles of the descendents of his maternal relatives , yet this would provide results that were far from irrefutable; apparently unrelated individuals have been known to share an unknown maternal relative at some point in the distant past (Melton, 2002, I), and recent research has suggested that mtDNA can mutate in maternal descendents faster than has previously been thought (Gibbons, 1998, pg 28). Clearly, it is uncertain whether or not the mtDNA markers on the mixed donor Sickert letters are actually Sickert's; however, if this difficulty is temporarily waived, and the mtDNA markers are assumed to be his, further problems arise in making the assertion that these markers are from the same person as those found on the single donor mtDNA profile Ripper letter sent to Dr. Openshaw. Cornwell's estimate that the single donor mtDNA profile of this Ripper letter is specific enough to eliminate 99 per cent of the population as the person who wrote it is disputed, and it has been claimed that the percentage would, more accurately, range anywhere between 90 and 99.9 per cent (Cohen, 2002, I). In 1901, little more than a decade after the Whitechapel murders, the UK population was almost 40 million (Ryder, 2004, I), and thus if Cornwell's frequency statistic was still retained, it would, alone, enable no more than 400,000 people to be eliminated for writing the letter. Accordingly, it may be seen that even if it is assumed that the mtDNA markers on the mixed profile Sickert letters were actually those of Sickert, it remains a pre-emptive leap to conclude that, just because the same markers were found on the single donor mtDNA Ripper letter to Dr. Openshaw, Sickert must have been its author. However, if this difficulty is waived again, and it is assumed that Sickert wrote the Ripper letter to Dr Openshaw, further problems emerge in suggesting that this reveals him as Jack the Ripper. During the Whitechapel murders, the City and Metropolitan Police received as many as 1200 letters a week (Palmer, 1995, pg 123), some from as far away as America, Australia and South Africa (Ryder, 2004, I), purporting to be from Jack the Ripper; the vast majority of these letters are considered to be hoaxes (Begg et al, 1994, pg 211; Palmer, 1995, pg 123; Eddleston, 2001, pg 155; Evans & Skinner, 2002b, pg 54; Sugden, 2002, pg 263; Ryder, 2004, I). Only one Ripper letter, that sent to George Lusk on 15 October, 1888 , which contained a piece of kidney, later determined by Dr. Openshaw to be human, is widely considered to be genuine (Evans & Skinner, 2002b, pg 61). The authenticity of the letter sent to Dr. Openshaw, upon which Cornwell found the mtDNA markers that were the same as those on the Sickert letters, is doubted (Eddleston, 2001, pg 263; Ryder, 2004, I), primarily because, as with many other hoaxes, it responded only to the events which had been made common knowledge by the London newspapers (Evans & Skinner, 2002b, pg 263). Accordingly, even if it was proved that Sickert had written the letter to Dr Openshaw, it would still constitute no cogent basis for asserting that he was anything more than a hoaxer adopting the persona of Jack the Ripper.
Cornwell also attempted to employ fingerprinting as a forensic tool in her investigation yet her attempts were in vain; she found only two fingerprints on a Ripper letter, sent eight years after the Whitechapel Murders in 1896, and two partial fingerprints on a Sickert painting and etching plate (Cornwell, 2002, pg 163). She affirms that her forensic team are currently using image enhancement techniques to sharpen the characteristics of the partial prints (Ibid, 2002, pg 164), yet even if they succeed , any evidence would face problems similar to those encountered by the DNA results addressed above; namely, establishing that the fingerprints on the Sickert items were Sickert's, determining whether or not these could reasonably be said to match those on the Ripper letter , and deciding whether or not, if they did, the Ripper letter was real, or, as is much more probable, a hoax.
Ripper letters revisited
Cornwell believed that the mtDNA results of her tests 'clinched the case' against Sickert, yet they did not constitute the bulk of it; in seeking to reveal Sickert as Jack the Ripper, she granted much time to the attempt to prove that he wrote many of the Ripper letters. The aforementioned consensus that virtually all these letters were hoaxes will, for now, be set aside, and the means by which Cornwell endeavours to prove that Sickert wrote them illuminated. She suggests that a collection of Ripper letters were written on paper displaying the watermarks of manufacturers such as A Pirie & Sons, Joynson Superfine, and Gurney Ivory Laid, which corresponded with the watermarks on the paper used by Sickert for his letters (Cornwell, 2002, pg 219). However, there were only around 90 mills producing watermarked paper in the UK during the late 1880s, and with such a limited number to choose from it is unreasonable to assert that because the same type occurred in Ripper and Sickert letters, there is a significant chance that they emanated from the same individual (Cohen, 2002, I; Nickell, 2003, I; Ryder, 2004, I). Cornwell also attempts to prove that Sickert wrote many of the Ripper letters by elucidating how they contained names and phrases that he would have been likely to use; she asserts that because Sickert read Shakespeare, in which the word 'Jack' and variations of the word 'Ripper' appear, he would have been especially prone to devise the name 'Jack the Ripper' (Cornwell, 2002, pg 146), and also that because he adopted the name 'Mr. Nemo' in his days as an actor, and his friend James Whistler used the expression 'Ha Ha' in his company, he would have been predisposed to use these terms in Ripper letters, (Cornwell, 2002, pg 63). However, 'Jack' was a name with pre-existing criminal connotations , as obvious as any which could possibly have been chosen, and threatening variants of the word 'Ripper' also existed (Sugden, 2002, pg 259); furthermore, it was common practice in the 1880s to sign letters 'Nemo' as an alternative to 'Anonymous' (Ryder, 2004, I), and the use of the expression 'Ha Ha' has been widespread since the times of Old English (Cohen, 2002, I). It is untenable to hold that Sickert had any special tendency to use these names and phrases, and still more untenable to suggest that their presence in Ripper letters indicates that he wrote them. Another method by which Cornwell tries to demonstrate that Sickert wrote many of the Ripper letters is to outline how their mention of music halls, theatres and racecourses reveals a geographical profile which resembled that which would be expected for Sickert himself (Cornwell, 2002, pg 198). However, such venues were highly popular in the 1880s, and their mention in Ripper letters reveals a geographical profile no more exclusive to Sickert than to the many thousands of other individuals who frequented them; certainly, it would be unreasonable to claim that such a geographical profile significantly increased the likelihood that Sickert wrote any of the Ripper letters. Each piece of evidence which Cornwell suggests prove Sickert wrote the Ripper letters can be strongly challenged; when it is remembered that an almost unanimous agreement exists that nearly all of these letters are, in any case, hoaxes (Begg et al, 1994, pg 211; Palmer, 1995, pg 123; Eddleston, 2001, pg 155; Evans & Skinner, 2002b, pg 54; Sugden, 2002, pg 263; Ryder, 2004, I), her attempt to unmask him as Jack the Ripper by this method becomes mortally wounded.
Psychology of a psychopath
Some authors have highlighted the utility of psychological profiling as an investigative tool in Ripper studies (Begg et al, 1994, pg 139; Eddleston, 2002, pg 276; Sugden 2002, pg 468), and Cornwell employed it to reveal that, since boyhood, Sickert's character traits had been 'typical' of those possessed by violent psychopaths such as Jack the Ripper (Cornwell, 2002, pg 62). Sickert never wrote a biography and the major writings about his life were made by others, after his death, on the basis of second hand accounts; consequently, their validity as evidence from which a representative psychological profile could be extrapolated for Sickert must be considered debatable. A further problem arises in that the information conveyed by these sources about Sickert, however valid in itself, is misrepresented by Cornwell; details about his personality are included or excluded on merit of how well they fit with those which Cornwell claims are indicative of a psychopath. Cornwell's justification for positing that Sickert had a psychological profile which would have prompted him to commit the Whitechapel murders lies chiefly in her assertion that he had a penile fistula. She suggests that horrific operations undertaken to correct the problem when he was a boy left him mutilated and sexually dysfunctional; in turn, she postulates that this had devastating repercussions in his psyche, and instilled a 'loathing' for women within him which he felt compelled to avenge (Cornwell, 2002, pg 7). It is known that Sickert had a fistula, though it is not certain that it affected his penis. This information came from John Lessore, Sickert's nephew, who has since dismissed it as family hearsay (Ryder, 2004, I); furthermore, Sickert was treated by Dr. Alfred Cooper of St. Mark's hospital, who was only qualified to perform operations for fistulas of the rectum, anus and vagina (Ibid, 2004, I). Even if Sickert's fistula was on his penis, it is known that the problem was successfully corrected by Cooper's operation (Sutton, 1976, pg 19), and that it did not transform him into the sexually incapable misogynist which Cornwell suggested. Sickert was divorced from his first wife, Ellen Cobden, for his habitual adulterous affairs with other women (Ibid, 1976, pg 80) and he continued to have sexual and loving relationships with several other women during his lifetime, siring at least one child (Ibid, 1976, pg 100). Cornwell (2002, pg 56, 61) also ventures that, as with many psychopaths, Sickert evolved an evident 'coldness' and 'self absorption' as a child which persisted all his life and estranged him from his parents and friends. However, it is known that Sickert was devoted to his mother, and kept her portrait with him at all times, and also that he greatly admired his father, frequently claiming that he remembered everything he had told him (Sutton, 1976, pgs 14, 31, 100); furthermore, a 'talent for friendship' was known to be one of his gifts, and he had many throughout his life (Ibid, 1976, pg 102). In an attempt to consolidate the cogency of her abstraction that Sickert had the psychological traits of a psychopath, Cornwell entertains the notion that he was both manipulative and defiant, supporting this through the claims that he often changed the rules of chess to suit himself when playing, and that he was expelled from his school (2002, pg 60, 62). In fact, Sickert invented a game called 'Sedan' for his friends, with rules that were based upon those of chess and established and agreed before a game commenced (Sutton, 1976, pg 24) and was expelled from his school for nothing more mischievous than selling doughnuts to other pupils (Browse, 1960, pg 14). Owing to the significant doubts concerning the validity of the information conveyed in the accounts of Sickert's life, and the outright misrepresentation of this information by Cornwell, her assertion that Sickert had a psychological profile which would match that expected for a psychopath such as Jack the Ripper can be granted little, if any credit. One of the few psychological profiles for Jack the Ripper is that devised by Douglass in 1988, (Begg et al, 1994, pg 139; Eddleston, 2001, pg 154; Sugden, 2002, pg 469); this was formed purely on what is known of the Ripper crimes, without any vested interest in a particular suspect; interestingly, this still reveals a personality which bears little resemblance to what is known about Sickert's (Table 2).
Table 2. (Source; Begg et al, 1994, pg 139; Eddleston, 2001, pg 154; Sugden, 2002, pg 469)
|Characteristics of 'Jack the Ripper'||Characteristics of Walter Sickert|
|Domineering mother and absent father.||Loving relationship with both parents, sustained throughout his life.|
|Developed destructive emotions in younger years, expressed by lighting fires and mutilating animals.||No such tendencies ever noted.|
|An asocial loner; quiet and shy.||Had many friends and adept at making new ones.|
|A hatred for and disgust with women.||Had many female lovers and friends.|
|An occupation which enabled him to experience his destructive fantasies; possibly a butcher, or a hospital or morgue attendant.||Worked as an artist.|
|Unmarried.||Married at time of Ripper murders, and married twice more later in life.|
|Lived in Whitechapel||Lived in 54 Broadhurst Gardens, South Hampstead, during Ripper crimes, though had artistic studios in Whitechapel.|
The art of murder
Cornwell asserts that the contents and themes of Sickert's artwork reveals that he possessed an intimate knowledge of the Whitechapel murders, and a violent, psychopathic mind, and concludes, in turn, that this gives a strong indication that he was Jack the Ripper (Cornwell, 2002, pg 14). The interpretation any piece of art is highly subjective, and individuals often assign meaning to it which they hoped or expected would be present, thus granting it an association which was never the intention of its creator, and simultaneously raising severe doubts about the cogency of its evidential value (Cohen, 2002, I; Yeh, 2003, I; Ryder, 2004, I; Vanderlinden, 2004, I). Though Cornwell's endeavour to use Sickert's artwork to incriminate him as Jack the Ripper seems methodologically flawed from the outset, her claims may be challenged more directly. She suggests that, due to facial similarities, and a dark line around her throat, like a deep cut, the female figure in his sketch Venetian Studies, was, in fact, intended to depict the Ripper's first victim, 'Mary Ann Nichols', and similarly that, due to the poor distinction of her facial features, the female character in his painting Putana a Casa was deliberated to resemble the Ripper's fourth victim, 'Catherine Eddowes', who had her nose slashed, (Cornwell, 2002, pgs 148, 294). However, it is known that these artworks were created ten years after the Ripper murders whilst Sickert was in Venice (Vanderlinden, 2004, I), and that he based them directly upon models which reoccur in his paintings (Sutton, 1976, pg 123; Shone, 1988, pg 32; Baron & Shone, 1993); furthermore, the 'dark line' around the female's throat in Venetian Studies appears clearly to be a beaded necklace, and the indiscriminate facial features of the model in Putana a Casa are replicated in many of Sickert's portraits and are indicative of his individual artistic technique (Vanderlinden, 2004, I). Even if these considerations were waived and it was assumed that the women did represent Nichols and Eddowes, Sickert need not have been Jack the Ripper to have seen them; it is feasible that he could have visited them in the morgue, and seen a photo of Eddowes in Lacassagnes's Vacher l'Eventreur, a book published in 1899 (Ryder, 2004, I). Cornwell (2002, pg 14) also refers to a Sickert painting called The Camden Town Murder or What shall we do for the rent? in which a man sits upon a bed, next to a prostitute he has apparently just murdered, suggesting that this evoked the earlier Whitechapel Murders. There had been a murder of a prostitute in Camden Town, which had fast become a local legend (Browse, 1944, pg 25), and it seems probable that Sickert's painting was inspired by the actual event itself, as opposed to the Whitechapel murders almost twenty years earlier. Cornwell (2002, pg 150, 253) suggests that Sickert divulged his destructive fantasies in his art, suggesting that in his many sketches of London's music halls he continually drew dismembered female body parts, and that most of his paintings of nude figures appear to be dead, or at least, at risk from impending death. In fact, the supposed 'dismembered' body parts appear to be anything but Sickert's studies of limbs in different postures, sketched to improve his technique (Robins, 1996, pg 23) and the nudes in Sickert's paintings, far from lying dead, or in grave danger, are distinctive chiefly for mundane actions, perhaps dressing, washing, lying down, or sitting (Shone, 1988, pg 32). The use of artistic analysis to infer psychopathic tendencies in Sickert seems methodologically flawed, and fails to provide any cogent evidence to reveal him as Jack the Ripper.
Although the keystones of Cornwell's argument for asserting that Sickert was Jack the Ripper have been illuminated and their validity questioned there are several more significant difficulties which should be mentioned. It appears that, from mid August, Sickert stayed in France for several months and was hence not in London when the Whitechapel murders occurred; on September 6th, only six days after the first murder and just two days before the second, Sickert's mother wrote to a friend and described how Sickert and his brother had been in France, whilst later, Sickert's friend Jacques Emile Blanche, in France at the time, wrote to his father, recounting a visit he had received from Sickert on September 16th, and his wife Ellen also wrote to her brother in law on September 21st elucidating how Sickert had been in France for several weeks (Dean, 2002, I; Nickell, 2003, I; Ryder, 2004, I). Cornwell's study also pays minimal attention to the other Ripper suspects; there are well over a hundred of these (Eddleston, 2001, pg 195), the most compelling being outlined in Table 3, though she grants a fleeting mention only to three , and does little to eliminate these, or any others, as a means of increasing the weight of the case against Walter Sickert. Cornwell's investigation is also characterised by a persistent selective exclusion of information which would stand to contradict her theory, a complete lack of footnotes and references, and an inadequate bibliography (Cohen, 2002, I).
Table 3. (Source; Palmer, 1995, Chap 3; Eddleston, 2001, Chap 11)
|Name of Suspect||Grounds for Suspicion|
|Aaron Kosminski (1864-1919)||A resident of Whitechapel. Became insane and matched witness descriptions of Jack the Ripper. Strongly suspected by the authorities of the day.|
|Frederick Bailey Deeming (1842-1892)||Murdered his wife and children in England before moving to Australia. When on trial for the murder of his second wife here he made a confession that he was Jack the Ripper.|
|George Chapman (1865-1903)||A resident of Whitechapel. Matched witness descriptions of Jack the Ripper and had some skill with the knife. Strongly suspected by the authorities of the day.|
|James Maybrick (1838-1889)||Rented a room in Whitechapel. Named as the author of a sixty three page diary written signed Jack the Ripper. Had a watch with the name Jack the Ripper inscribed upon it, and the initials of his five victims.|
|Montague John Druitt (1857-1888)||Sexually insane. Shortly after he died the Whitechapel Murders stopped. Strongly suspected by the authorities of his day, yet only after his death.|
|Michael Ostrog (b. 1833)||A resident of Whitechapel. Became insane and evaded police probation during the Whitechapel Murders. Strongly suspected by the authorities of the day.|
|Nicholas Vassilly (b. 1842)||A resident of Whitechapel. Had murdered five prostitutes in Paris and was confined to an asylum. He was released and went to London in 1888, his arrival coinciding with the Whitechapel Murders.|
|Thomas Neill Cream (1850-1892)||Escaped from prison in America in 1888 and frequented Whitechapel. Poisoned several prostitutes in Lambeth in 1891 and 1892 and wrote taunting letters to the Police. As he was being hanged in 1892, his last words were 'I am Jack the...'|
|Prince Albert Victor, Duke of Clarence (1864-1892)||The Prince contracted syphilis of the brain from a prostitute. Often suggested that he wished to avenge this and that a Masonic conspiracy evolved to hide his guilt.|
|William Withey Gull (1816-1890)||A surgeon, and much skilled with the knife. Suggested he was involved in the Masonic conspiracy plot and sometimes asserted to be Jack the Ripper.|
Cornwell remarked that she was '100 per cent' certain that Walter Sickert was Jack the Ripper, and went so far as to stake her reputation upon the claim (ABC News, 06/12/2001, I). In seeking to bolster her theory, she employed an extensive range of techniques from the forensic repertoire, many of which had never before been applied to a Ripper investigation. She claimed to have unearthed irrefutable DNA evidence, and asserted that fingerprint tests were in the process of being conducted; she also suggested that she had evidence linking Sickert to the many Ripper letters, in addition to positing that he had a psychological profile identical to that which would be expected for Jack the Ripper and asserting that his sketches and paintings revealed intimate knowledge of the Whitechapel Murders. Yet her exertions have been largely futile; the methodological frameworks which she employs are severely flawed and the conclusions which she reaches can hence be granted little credence. It is ventured by The Guardian (08/12/2001, I) that the hunt for the elusive identity of Jack the Ripper has traditionally inspired 'crackpot conspiracy theories', 'elaborate frauds' and 'career destroying obsessions'; it is difficult to ascertain into which of these categories Cornwell's Portrait of a Killer falls. Despite her best efforts to prove and persuade otherwise, the case remains open, and its mystery surely less threatened than her own reputation.
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1. This is owing to the highly specific class of the population to which the victims belonged, and the characteristic manner in which their bodies were mutilated.
2. The DNA degradation was doubtless due to the influence of heat, applied when the letters were laminated before being archived, yet also to the sub-optimal conditions in which they were stored for over a hundred years (Cornwell, 2002, pg 207).
3. Mitochondrial DNA, found in hundreds of copies in the mitochondria of human cells, and inherited almost completely from the mother (Lodish et al, 1986, pg 812), has become a widely accepted tool for forensic application (Leland Davis, 1998, I); it has been used to identify the remains of dead servicemen (Huskey, 2001, I), and has also been employed as evidence in criminal cases (Melton, 2002, I). The tests for mtDNA are far more time consuming than those for nuclear DNA, and they are accordingly conducted only when the available sample is either small, or degraded (Ibid, 2002, I).
4. As mtDNA is maternally inherited, the descendents of any maternally related individuals would be expected to share the same mtDNA profile (Melton, 2002, I).
5. This letter is lost, and was unavailable for any of Cornwell's DNA testing.
6. No results have yet been made public, and it is not known that any are, as yet, forthcoming.
7. Although fingerprints have long been thought to be unique to an individual, and thus possessed of a much greater discriminating power than mtDNA sequences, Randerson & Coghlan (2004, pg 6) have recently asserted that there is, at present, no statistically satisfactory means of determining whether identical fingerprints emanate from the same person.
8. Many criminal celebrities, real and fictional, appeared in Penny Dreadfuls who went by the name Jack; these included 'Jack Sheppard', 'Sixteen String Jack' and 'Spring Heeled Jack', (Sugden, 2002, pg 260).
9. These are James Maybrick, Montague John Druitt and the Duke of Clarence (Cornwell, 2002, pgs 207, 136).