AFIS Scores

[anwilson]

I use the scores to screen my case workflow for efficiency purposes. When I worked cases on a daily basis I would batch my AFIS work. The scores are a way to do a quick screen of which cases I will focus on first. If there's a huge gap in scores between the 1st and 2nd candidate it's almost always going to be a hit. Since cases with IDs go quicker I focus on cases with hits first while chugging along on no-hit cases. This allows me to clear hit cases from my desk so I can then ask for more cases to work. I always had a rotating drawer of cases coming in and out daily which led to higher productivity.

[NRivera]

In 2017 we worked 4151 Cases with a total of 14346 Impressions of Value (AFIS or Subject Value) , 1478 Individualizations that came directly from AFIS (approximate hit source = 80% local, 19% NGI, 1% WIN), 29128 Total Evaluations and 1238 distinct subjects Identified.

Our current minimum AFIS standards are:

Required Run:
8-12 objective features with additional non galton data and known area/orientation
OR
12 Objective Features with known area/orientation without additional non-galton data
OR
16 objective features and unknown area/orientation

Examiner's discretion:
8-12 objective features with no additional non-galton data

Edit: I forgot to mention that impression to be run is likely to be part of the capture of a standard ten print/palm card.

We've got different lingo so I think I lost you slightly. "Impression to be run is likely to be part of the capture of a standard ten print/palm card." Does this mean your count for impressions includes known prints of suspect/victim/witness/others involved in a case? Also, "non-galton data", I'm understanding that to mean maybe demographic info like race/gender/physical characteristics, etc.

We take a substantially different approach simply because of the nature and scope of what we work. We rarely get victim elimination prints and we are liable to hit on any number of non-suspect actors depending on the type of case. Most of the time, there is no added benefit from narrowing the search down to a geographical area either. We also don't deal with ten-print comparisons at all unless a case is going to trial and we need to confirm the downloaded FP record to establish foundation.

[anwilson]

Likely to be on a standard tenprint card means we're not required to run tip impressions because tips aren't typically recorded on a tenprint card (although I tend to run them if it looks like a tip from a thumb or appears somewhat close to the core).

We use non-Galton features to mean pores, incipients, scars, ridge edges.

[NRivera]

I see said the blind man! We just call that L3D.

[Boyd Baumgartner]

It's just that over time, the distinctions of L2 and L3 have become so squishy, we pulled a Gilligan's Island 'And the rest' strategy for anything that's not a minutiae.

For instance Chapter 9 of the Fingerprint Sourcebook says:

9.2.2.4 Levels of Detail of Other Features. First, second, and third levels of detail can also describe other features
(e.g., creases, scars, incipient ridges, and other imperfections) from volar skin represented in a print. First level details describe the general directions and positions of the features. Figure 9–5 depicts the general direction of creases, scars, and imperfections.

Second level details of creases, scars, or imperfections are the actual paths of the specific features. The actual path includes the starting position of the detail, the path it takes, the length of the path, and where the path stops. A second level detail is much more than the location where a feature stops or bifurcates. Second level details of these features do not require the path termination to occur. A continuous path from one end of the print to the other end of the print is included within the definition of second level details. Second level details of other features cannot exist without first level details of the same features. Figure 9–6 depicts general direction and specific paths of creases, scars, and imperfections.

Third level details of creases, scars, or imperfections are the morphologies or shapes within their structures. This level of detail encompasses the morphological edges and textures along or upon the feature. Third level details of a crease, scar, or imperfection cannot exist without first and second levels of these details.

So, even your level 3 can have level 2 or even level 3.

And don't forget this study

A survey of 200 fingerprint examiners found disagreement among them about the classification of proposed print characteristics either into different levels or as artifacts