Presentation on theme: "Document Analysis. Document examination is a form of forensic science that includes the analysis of handwriting as well as the detection of forged documents."— Presentation transcript:
Document examination is a form of forensic science that includes the analysis of handwriting as well as the detection of forged documents such as passports.
What does forensic document examination mean? The application of allied sciences and analytical techniques to questions concerning documents is termed forensic document examination. The examination of questioned documents consists of the analysis and comparison of questioned handwriting, hand printing, typewriting, commercial printing, photocopies, papers, inks,
What does forensic document examination mean? and other documentary evidence with known material in order to establish the authenticity of the contested material as well as the detection of alterations.
Equipment used in Document Analysis Forensic investigators have access to several machines that enable them to read a letter where the ink has been washed away, see what lies beneath scribbles and read a letter from indentations left on another sheet of paper:
Equipment used in Document Analysis Electro Static Detection Apparatus Video Spectral Comparator Thin Layer Chromatography Infrared Reflectance
Electro Static Detection Apparatus An Electro Static Detection Apparatus is used to visualize indentations by applying an electrostatic charge to a transparent film. The film is laid across the page in question and once the charge has been applied, black toner is passed across the film and reveals any indentations. This method can also determine if something has been added to a journal or log after the original entry was made
Electro Static Detection Apparatus This non-destructive test readily permits the fast and routine examination of all suspect documents.
Video Spectral Comparator A Video Spectral Comparator is used to analyze inks and see whether they are the same or different. This is done by looking at them under different lighting conditions where some wavelengths of light are blocked. This technique can uncover layers in documents where words have been scribbled out or written over
Video Spectral Comparator Light source for document examinations and verification of official documents
Thin Layer Chromatography Thin Layer Chromatography is used to do a more thorough analysis of ink. The ink is mixed with chemicals and deposited onto a silicate plate where its constituents can be measured
Infrared Reflectance Infrared Reflectance is used to show the residue of pencil marks. This can be done clearly even if the writing has been erased. Pencils are made of graphite which is a form of carbon – and this absorbs infrared light well
Uses of Handwriting Analysis ► Determine identity of writer In ransom notes In document forgery In death threats In suicide notes Can you think of others? Forensic Document Examiner
Comparisons Are Useful Because ► No two people have identical handwriting ► By adulthood, it is exclusive to an individual (we all learned the same techniques to begin writing in grade school) (we all learned the same techniques to begin writing in grade school) ► Even disguised handwriting will exhibit some of the will exhibit some of the person’s individual person’s individual characteristics characteristics Forensic Document Examiner
Standard Comparisons ► Include sample to be analyzed called an EXEMPLAR ► Samples from an individual include Collected writing comes from prior to the beginning of the investigation (helps prevent or indicate when a person is disguising their handwriting) Requested writing is a dictated text using the same type of paper Same type of ink as the sample to be analyzed
Forensic Document Examiner ► The best thing to examine is something with the same words as the document in question. ► An examiner may dictate to a potential suspect, slowly then faster so that they have less chance of disguising the handwriting. ► Use same ink and paper (as said before) pencil, ballpoint pen, fountain pen, marker, etc.
Forensic Document Examiner ► List ways a person may change or attempt to disguise their handwriting
Forensic Document Examiner ► Name items that you could get from a potential suspects home to use for handwriting identification.
Forensic Document Examiner ► Handwriting originates in the brain when a mental picture of letters and words is formed. The signal to try to duplicate the mental picture is sent to the arm and hand through the muscles and nervous system. The actual output is almost never an exact match of the original mental picture.
Forensic Document Examiner Handwriting is distal, meaning that it occurs at the extremities and involves fine motor activity as opposed to a skill like walking which is proximal - a large, or gross motor skill. One reason individuals find it difficult to simulate the handwriting of others is that to do so successfully requires understanding the essence of the writer's motor control program and executing that same program.
Forensic Document Examiner ► Some typical document examination questions ► Is the signature genuine? ► Is the document forged, and if so is it forged by a particular person? ► Is the same person the author of several documents? ► Did someone guide a person's hand as a will was signed? ► Did the doctor come back later and alter the medical records? ► Did the signer of the document also initial the changes? ► What is written under the crossed out portion of the writing? ► Was the document written on the date indicated?
Forensic Document Examiner ► Some typical document examination questions ► Are there erasures on the document? ► Are there alterations or obliterations on the document? ► What was originally written before the alteration or under the obliteration? ► Are there perforations, folds, staple holes, or other physical clues on the document ? ► Was the entire document rewritten, or was it prepared sequentially, over a period of time?
Shredded Material Recovery ► The purpose of our work was to turn bags of shredded documents like these...
Shredded Material Recovery ► Into legible documents like these...
Shredded Material Recovery ► Which involved separation of individual shreds from the pile and re-assembling them piece by piece.
Shredded Material Recovery ► Each bag of shredded paper contained an average of 100 recoverable documents.