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As An Attorney What You Should Expect From A Latent Expert
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As An Attorney What You Should Expect From A Latent Expert

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Some thoughts on fingerprint errors and how they may be prevented or corrected.

Some thoughts on fingerprint errors and how they may be prevented or corrected.

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As An Attorney What You Should Expect From A Latent Expert Presentation Transcript

  • 1. “ Justice denied anywhere diminishes justice everywhere ” Martin Luther King Jr .
    • Recently in a discussion with a defense attorney, I realized the
    • attorney was not aware of the recent issues surrounding the
    • fingerprint process and potential for error. Realizing an attorney
    • needs to keep up with myriad of forensic disciplines, I decided to do
    • a brief informational PowerPoint. I’m a strong proponent of
    • fingerprints and Automated Fingerprint Identification Systems but I
    • realize and understand that errors in fingerprint processing and
    • Identification will occur. Errors can be the result of the Automated
    • Fingerprint Identification System or the fingerprint examiner with a
    • questionable or bad comparison.
    • While discussions seem to center on a certification program as the
    • way to reduce error and improve accuracy, as with most things, the
    • issues and answers are more complex. The current adversarial
    • judicial process is the most effective tool in minimizing the number
    • of inaccurate identifications. Unfortunately the adversarial judicial
    • process is not utilized as much as it could be resulting bad/missed
    • identifications. Agency administrators and examiners often look at
    • missed identification as not as serious a problem as a bad
    • identifications, this is a mistake. I explain later in this presentation
    • how a missed identification can be as devastating to a case as a
    • bad identification. This presentation is designed to provide
    • information on what a trial lawyer should consider when confronted
    • with a case involving fingerprints or a questioned criminal history.
  • 2. Latent Facts
    • Average size of a latent fingerprint fragment about 20% of a full fingerprint.
    • Typical latent fingerprint has between 15 and 35 minutiae (points of identification).
    • Typical inked fingerprint contains between 75 and 175 minutiae (points of identification).
    • latent images recovered from crime scenes are of poor clarity, increasing the likelihood of mistaking the type of minutiae being observed.
    • 30% of crime scenes have usable latent images.
    • 30% of the images from a crime scene are palm images.
    • A palm print has approximately 800 minutiae (points of identification).
    • 20% of identifications at local lab's are now generated by the automated fingerprint search system.
    • Latent search accuracy can be as low as 54% on a large database, to mid 80% with good image clarity under controlled conditions.
  • 3. Possible causes of Error found in the Fingerprint Process
    • Erroneous Bad Identification :
      • Examiner just makes a bad decision.
      • Analysis, Comparison, Evaluation and Validation (ACE-V) procedure not followed.
      • Confirmation Bias.
      • Identification based on to few minutiae for the clarity of the image.
      • Inexperienced, poorly trained or part-time latent examiner.
      • Reluctance of latent print unit to document the characteristics used in the examination.
    • Questionable Identification :
    • Analysis, Comparison, Evaluation and Validation (ACE-V) procedure not followed.
    • Peer Investigative pressure
    • Confirmation Bias.
      • Identification based on to few minutiae for the clarity of the image.
      • Inexperienced, poorly trained or part-time latent examiner.
      • Reluctance of latent print unit to document the characteristics used in the examination.
    • Latent not thoroughly searched in automated fingerprint system.
      • Procedure not followed or lack of policy and procedure.
      • Inexperienced, poorly trained or part-time latent examiner.
    • Missed Identification:
      • Procedure not followed or lack of policy and procedure.
      • Suspect checked by unqualified latent examiner.
      • Inexperienced, poorly trained or part-time latent examiner.
    • Automated search system database search images:
      • Procedure not followed or lack of policy and procedure.
    • Criminal History contains erroneous criminal events:
      • Procedure not followed or lack of policy and procedure.
      • Examiner just makes a bad called.
      • Many agencies do not use double verification on arrest card processing.
      • Lights out functionality not properly applied.
      • Identification based on to few minutiae for the clarity of the image.
      • Inexperienced, poorly trained or part-time fingerprint examiner.
    • Latent image processing:
    • Procedure not followed or lack of policy and procedure.
  • 4. Erroneous Identification
    • Causes:
    • Examiner just makes a bad called.
    • Analysis, Comparison, Evaluation and Validation (ACE-V) procedure not followed.
    • Confirmation Bias
    • Identification based on to few minutiae for the clarity of the image.
    • Inexperienced or part-time latent examiner
    • Reluctance of latent print unit to document the characteristics used in the examination
    • Prior to the automated fingerprint systems, law enforcement agencies that had unidentified latent images would file them away in case folders. Agencies had no way to
    • search these unidentified latent images. Today the automated systems are searching these unidentified latent images against databases containing as many as 600 million
    • fingerprint images. The systems are producing a large number of identifications in addition to the identifications the system is producing a large number of false positives.
    • The false positive suspects being produced often have minutiae (points of identification) which are quite similar in type and orientation to the latent being searched. When
    • you factor in the lack of clarity and distortion, you can understand why you are seeing more erroneous identifications. The question that comes to mind should be how many
    • bad identifications are not being discovered and corrected. The challenging comparisons associated with the automated latent fingerprint searches require the latent
    • examiner to be highly skilled and experienced. In the Mayfield case the FBI examiners felt they had 10 features in the latent that formed a constellation of points that was
    • generally consistent with the constellation of points in the known fingerprints of both Mayfield and Daoud. Mayfield was a suspect generated by the FBI automated fingerprint
    • search system. As is clear below the latent image lacked clarity and there was distortion. FBI procedure required they analyze, compare, evaluate and validate (ACE-V)
    • before declaring an identification. Four (4) experienced latent examiners made an erroneous call. This latent ,as with many that are brought to court, required the examiner
    • make a subjective decisions on minutiae based on training and experience. These more challenging afis comparisons do benefit public safety but we need to insure that it is
    • evaluated by an unbiased experienced latent examiner to minimize the chance of error.
    • Point to remember, if the Spanish examiners had not identified the latent print to another individual, Mayfield would have been convicted, based on the
    • fingerprint evidence.
  • 5. Questionable Identification Causes: Investigator/Peer Pressure. Confirmation Bias. Identification based on to few minutiae for the clarity of the image. Inexperienced or part-time latent examiner.
    • A questionable identification is one where a qualified latent examiner does not have enough minutiae (points of identification) to justify declaring
    • an identification. This is a situation where you may see peer or backward bias. When the clarity of an image is poor the minutiae (points of
    • identification) required for individualization increase. The comparison and evaluation of minutiae in an individualization is based on the
    • examiners training and experience. There are situations where the absence of sufficient friction ridge detail does not allow the examiner to
    • Effect a conclusion of individualization or exclusion. As the clarity of a print decreases, the actual physical area or number of features required
    • For making an Identification should increase.
    • March 2009, San Jose police never told anyone when fingerprint technicians could not agree about whether a suspect's prints matched those
    • taken from the crime scene. Instead, the police department's Central Identification Unit generated a report indicating that two technicians agreed
    • the suspect's prints had been positively individualized, while omitting a 3 rd . Latent examiner dissented. While this may have been a good
    • identification it’s a flag the attorney should have the images evaluated.
  • 6. Training and Proficiency
    • Boston P.D . two (2) fingerprint lab examiners testified that a fingerprint from a drinking glass used by the assailant matched Cowans’. He was sentenced to 35 to 50 years in prison.
    • DNA testing revealed the error. An investigation of the misidentification concluded that poor training of the department’s fingerprint analysts was to blame for the blunder. Finding that the examining officers were not prepared to do complex fingerprint analysis, the report said the unit did not train its officers to keep up with standard practices in fingerprint analysis and had low performance standards. The unit had little or no protocol or standardization of procedures. This resulted in the closing of the Lab. and training all new civilian examiners. The error would not have been found and corrected if not for the Innocence Project .
    • L.A P.D. is in a similar situation, discovery of two (2) bad identifications has led to the review of close to 1,000 latent cases. Again a situation where policy/procedure and training will be a contributing factor in the errors.
  • 7. What happens when a latent image is only searched once in the Automated Fingerprint Identification System, is it truly a non-ident ? The answer is positively, Maybe
    • Latent and tenprint image clarity as well as the size of the database play a big roll in whether a latent image is identified on its initial search in
    • the Automated fingerprint database. I can tell you from experience, there are a significant numbers of tenprint arrest cards in most search
    • databases with poor clarity that negatively impact a latent search. Many agencies, because of workload or lack of understanding of the system,
    • do not normally search a latent in the automated system more than once. National Institute of Standards and Technology (NIST) a few years
    • back tested the search accuracy of the major AFIS vendors and discovered an accuracy rate of between 54% and 85%. To get the 85%
    • accuracy requires the vendor test on a small database with a minimum of 15 minutiae on the latent and the corresponding minutiae are on the
    • target image in the search database. I don’t mean to fault the search systems which are producing good suspects resulting in fingerprint
    • Identifications, but agency procedures need to compensate for system limitations.
    • There is also another scenario where on the initial search the examiner missed an identification. In the 2 nd . Search hopefully the target is not
    • missed for a 2 nd . time. If a print that could be identified is not how does it impact your case ?
    • Whether a prosecutor or defense attorney, a missed identification on an unidentified latent can have a major impact on your case or client. It
    • could produce the individual that was responsible for a criminal act or a witness that may be able to add more detail to a case. If not identified
    • the missed identification could lead to additional criminal acts by the individual or a wrongful conviction in the current case.
  • 8.  
  • 9. Understanding the Search Database
    • In addition to understanding the system accuracy, knowledge of the make up of the search databases will allow an attorney to insure the
    • fingerprint process was done correctly. Most afis search databases are made up of :
    • each individual arrest card processed.
    • composite of the best images from multiple cards
    • composite of points of identification from each card processed.
    • Recently some of the new systems began migrating to 1000 ppi image resolution. Agencies that have gone to a 1000ppi cannot convert the
    • search database completely to the higher resolution, so for a number of years the database will be made up of both resolutions. The FBI
    • database is still 500ppi and will remain at that resolution for quite a few years.
    • Will this impact search accuracy ? Of course, but there are no studies on how the system accuracy will be impacted running dual resolution
    • systems. In addition to how the search images are stored and searched, it is critical to know how the handles expunged records, or search and
    • return background checks. Are non-criminal cards part of the search database?
    • Knowing how the search images are stored and created is critical in determining if a suspect was legally available in the search
    • database. Some databases place no limits on what an agency can enter others require a state statute before retaining the fingerprint images.
    • With the proliferation of small local AFIS systems what is stored in a database can make or brake a case.
  • 10. Palm Searching
    • Most systems being purchased today have a palm search capability. A great benefit to image identification there will be significantly more Latent image individualizations. We can also expect an increase in errors with the same issue’s now encountered in fingerprint identification. While we increase the number of minutiae available the individualization is done exactly the same as a fingerprint individualization.
  • 11. Options
    • In today's electronic society you are no longer limited by geographic area in
    • obtaining competent and experienced latent examiner. The examiner you
    • chose could be from your area or from another state with today's digitized
    • Finger/palm print images. The latent case information and images can often be
    • sent via e-mail or certified mail. A CD, DVD or photographic copies of the
    • images along case information. In most cases the digitized image(s) will allow
    • an expert to make a decision on the image(s). I would recommend that you
    • view my other power point presentation on The Automated Fingerprint
    • Identification Systems as this will give you a better understanding of AFIS.
  • 12. Prosecutor/ Defense Attorney should expect from Today’s Latent Fingerprint Expert
    • As is clear from the preceding slides, a knowledge of the afis system is critical in
    • insuring that the fingerprints brought into court are accurate. The following are
    • things to consider when evaluating a fingerprint expert:
    • Experience in the individualization of latent fingerprints
    • Thorough knowledge of automated fingerprint identification systems
    • Latent search
    • Tenprint search
    • Database
    • Thorough knowledge of Criminal History Systems
    • Training and Proficiency standards
    • In today's world of electronic media, an expert can assist an attorney
    • Without having to be in the same city or even state. Images sent via e-mail,
    • CD, DVD or photographs can often contain enough information for an
    • expert to generate a detailed report on the latent case .
    • I have kept this brief, if you have specific concerns or questions on fingerprints, the
    • processing or automated search systems please contact me.
    Experience FBIS can offer clients: 15+yrs Latent Fingerprint Experience 15+yrs AFIS Experience 40+ yrs Fingerprint 4 yrs planning installation NYS 10 print AFIS IAFIS Remote BETA Testing Site Assisted with the Nebraska AFIS RFP
  • 13. Glossary of som e Terms
    • Bad Identification – examiner identifies a latent to the wrong tenprint card.
    • Backward Bias – examiners’ interpretation of some features is adjusted or influenced by reasoning “backward” from features that
    • were visible in Mayfield’s known prints.
    • Confirmation Bias- focusing on minutiae that confirms preconceived expectations while ignoring data that doesn't confirm ones beliefs.
    • Lights out functionality- System electronically individualizes a fingerprint.
    • One Discrepancy Rule- a single difference in appearance between a latent print and a known fingerprint must preclude an
    • identification unless the examiner has a valid explanation for the difference.
    • Peer Investigative Pressure – other examiners or investigative information to influence a comparison
    • Questionable Identification : Identification based on to few minutiae for the clarity of the image.
    • Single Verification- Many state agencies use a single verification procedure on arrest card processing error.
  • 14.  
  • 15.