Fingerprint Analysis

1. Fingerprint Analysis (Famous Cases)

2. Fingerprint Analysis • Forensic investigators have been using fingerprint evidence as a source of identification of suspects for over a hundred years.

3. Fingerprint Analysis   • Early work was by visual analysis of very obvious prints left at the scene of a crime

4.  Fingerprint Analysis • Modern forensic scientists now have a range of techniques for finding prints, cleaning up and enhancing print images, and rapidly finding a match from a database using computer technology.  

5.  Fingerprint Analysis Fingerprint evidence is seen as one of the best types of physical evidence linking a suspect to an object or location or for establishing identity.

6.  Fingerprint Analysis Therefore, the forensic investigator will always search for fingerprint evidence at the scene of a crime and at related locations, such as a suspect's home or car.

7.  Fingerprint Analysis A fingerprint is the pattern of ridges and related characteristics found on the finger pads, the fleshy parts of the fingers used for touching and gripping.

8.  Fingerprint Analysis Each person's fingerprints are unique and stay unchanged throughout life.

9.  Fingerprint Analysis According to Sir Francis Galton, the nineteenth-century English anthropologist, the chances of two fingerprints being identical are as small as 64 billion to one.

10.  Fingerprint Analysis In over a century of forensic fingerprinting, no two prints have ever been found to be the same, even those of identical twins.

11.  Fingerprint Analysis Skin is never completely dry or clean; grime, oil, and sweat on the finger pads create fingerprints whenever a person touches something.

12.  Fingerprint Analysis That is why criminals, unless they are wearing gloves, leave fingerprints behind.

13.  Fingerprint Analysis If their hands are bloodstained, then they will leave bloody fingerprints behind, an example of a patent (visible) print.

14.  Fingerprint Analysis Plastic prints are fingerprint impressions made in a soft material like soap or dust.

15.  Fingerprint Analysis Latent fingerprints are invisible, but the forensic scientist can visualize them though special lighting or with the application of chemicals.

16.  Fingerprint Analysis Fingerprints have been recovered from all kinds of surfaces, even plastic bags.

17.  Fingerprint Analysis * It would be very useful to be able to reliably detect fingerprints on human skin. * So far, this been very difficult to do if more than two hours have elapsed from the time the fingerprints were made.

18.  Fingerprint Analysis Potential methods are being developed to recover fingerprints after longer time periods have elapsed.

19.  Fingerprint Analysis A fingerprint found at the scene of a crime can be dusted with chemicals to make it easier to see and then lifted or photographed.

20.  Fingerprint Analysis It is then compared with the fingerprints of known offenders stored in a computer database.

21.  Fingerprint Analysis In the past fingerprints were classified according to the specific features that make up the unique pattern of each print.

22.  Fingerprint Analysis With computerized storage and retrieval systems, however, classification is not really necessary as the computer can readily scan and match the whole pattern of thousands of prints.

23.  Fingerprint Analysis The image of fingerprints found at the scene of a crime can readily be enhanced and clarified with scanning and digitizing technology.

24.  Fingerprint Analysis This means that even partial prints can be of value in identifying someone at the scene of a crime.

25.  Famous Case #1 In 1892 Francesca Rojas, an Argentine woman, became the first person ever to be convicted on fingerprint evidence.

26.  Famous Case #1 When her two young children were found beaten to death, she tried to blame a man called Velasquez who vigorously denied the charge and, in any case, had a firm alibi.

27.  Famous Case #1 Investigator Juan Vucetich, who was intrigued by the relatively new technique of fingerprint analysis, found a bloody fingerprint on a bedroom door in Rojas' house.

28.  Famous Case #1 He sawed the portion away and then had the woman give an ink-print of her thumb.

29.  Famous Case #1 Even with only a basic understanding of fingerprint analysis, it was obvious to the investigators that the bloody print belonged to Rojas.

30.  Famous Case #1 She confessed to the crime when confronted, and admitted that she committed the murders to improve her chances of marrying her boyfriend, who was known to dislike children.

31. Famous Case #1 Rojas was sentenced to life imprisonment.

32. Famous Case #2 • The brutal murder in 1905 of Thomas Farrow, manager of a shop in Deptford, near London, and his wife Ann was to become a milestone case in the use of fingerprint analysis in Britain.

33. Famous Case #2 • Money had been taken and a thumbprint was found on the cash box.

34. Famous Case #2 • The Criminal Investigation Department (CID) had already built up a file of fingerprints of known criminals, but this print did not match any of them.

35. Famous Case #2 • A witness led the investigators to two brothers called Albert and Alfred Stratton.

36. Famous Case #2 • A match was found between one of the men and the print found at the scene.

37. Famous Case #2 • The court battle over the evidence was, however, lengthy. • Much hung in the balance as it was the first time fingerprint evidence had been used in a murder case in Britain.

38. Famous Case #2 • After two hours of deliberation, however, the jury found the two men guilty and they were later hanged.

39. Famous Case #3 • In 1910, Thomas Jennings was arrested on suspicion of the murder of Clarence Hiller in Chicago.

40. Famous Case #3 • The main evidence against him was fingerprints, and four experts testified at his trial.

41. Famous Case #3 • However, fingerprint evidence was still relatively new and Jennings brought an appeal questioning its admissibility.

42. Famous Case #3 • In a landmark judgment, the Illinois Supreme Court upheld the conviction, saying that fingerprints were indeed a reliable form of identification.

43. Famous Case #3 • Jennings was sentenced to death and executed on February 16, 1912. • He was the first person in the United States to be convicted of murder on fingerprint evidence.

44. Famous Case #4 • Fingerprint analysis also played a role in convicting the man responsible for an audacious theft.

45. Famous Case #4 • On August 21, 1911, Leonardo da Vinci's Mona Lisa was stolen from the Louvre Museum in Paris.

46. Famous Case #4 • There was a clear fingerprint on the glass that had protected the painting.

47. Famous Case #4 • Fingerprint pioneer Alphonse Bertillon spent many months trying to match the print to samples in his collection but to no avail.

48. Famous Case #4 • Two years after the theft, police arrested Vicenzo Perugia in connection with the crime. • His prints matched those from the crime scene.

49. Famous Case #4 • Ironically, Perugia's thumbprint had been in Bertillon's collection all the time, but it was of his right thumb. • The one left on the glass in the Louvre was from his left thumb.

50. Fingerprint Analysis • Criminals soon realized that fingerprints could be used to convict them and took evasive measures.