Comparison phase of ACE-V
Procedural Steps:
A systematic, cyclical approach to comparing the friction ridge features previously observed in the Analysis phase for their correspondence in the known print. This is a "back and forth" examination, working from the unknown to the known. Begin with Level 1 examination observing the pattern type and ridge flow. Target a group of details in the unknown latent impression to be memorized for comparison against the known print. Observe the properties and characteristics of the friction ridge features (from Level 2 and Level 3) to search for a known print that is consistent with the friction ridge features observed in the unknown latent print impression. Examine the attributes observed during the Analysis phase to determine the agreement, or the presence of differences, between the friction ridge features.
Assessments are made for acceptable Tolerance Levels regarding the degree of Clarity, and for distortions/variations in appearance of the friction ridge features, if present.
The judgement made and the tolerance levels accepted are products of the training, skill and experience of the examiner. All examiners who are 'trained to competency' should be in general agreement regarding the assessments of clarity, distortion, and variation. However, the application of tolerance and clarity assessments to individual friction ridge features will vary. This variance is a natural product of the different skill and experience levels of practicing examiners.
Scientific Method / Daubert Issues Addressed:
The "back and forth" examination of the ACE-V Comparison phase is a prelude step in the Scientific Method outline.
In one essence, the Comparison phase is a "Population Reduction" process to Exclude known prints from further consideration in the ACE-V phases to follow. The Exclusion is accomplished through the "Observation" of Level One detail studied in the Analysis phase.
The extent to which the friction ridge features can be clearly observed and their attributes properly assessed in this Comparison phase will form the basis on which the Hypothesis (in the Evaluation phase) will be Proposed, Predicted and Validated in the Evaluation phase.
Additional Insights: (Click on)
Clarity
Tolerance Levels
Target
Group Relationship
Difference
Scientific Method
Copyright© 2010 Chesapeake Bay Division - International Association for Identification (IAI)
A systematic, cyclical approach to comparing the friction ridge features previously observed in the Analysis phase for their correspondence in the known print. This is a "back and forth" examination, working from the unknown to the known. Begin with Level 1 examination observing the pattern type and ridge flow. Target a group of details in the unknown latent impression to be memorized for comparison against the known print. Observe the properties and characteristics of the friction ridge features (from Level 2 and Level 3) to search for a known print that is consistent with the friction ridge features observed in the unknown latent print impression. Examine the attributes observed during the Analysis phase to determine the agreement, or the presence of differences, between the friction ridge features.
Assessments are made for acceptable Tolerance Levels regarding the degree of Clarity, and for distortions/variations in appearance of the friction ridge features, if present.
The judgement made and the tolerance levels accepted are products of the training, skill and experience of the examiner. All examiners who are 'trained to competency' should be in general agreement regarding the assessments of clarity, distortion, and variation. However, the application of tolerance and clarity assessments to individual friction ridge features will vary. This variance is a natural product of the different skill and experience levels of practicing examiners.
Scientific Method / Daubert Issues Addressed:
The "back and forth" examination of the ACE-V Comparison phase is a prelude step in the Scientific Method outline.
In one essence, the Comparison phase is a "Population Reduction" process to Exclude known prints from further consideration in the ACE-V phases to follow. The Exclusion is accomplished through the "Observation" of Level One detail studied in the Analysis phase.
The extent to which the friction ridge features can be clearly observed and their attributes properly assessed in this Comparison phase will form the basis on which the Hypothesis (in the Evaluation phase) will be Proposed, Predicted and Validated in the Evaluation phase.
Additional Insights: (Click on)
Clarity
Tolerance Levels
Target
Group Relationship
Difference
Scientific Method
Copyright© 2010 Chesapeake Bay Division - International Association for Identification (IAI)