Erroneous Exclusion vs. Missed Identification

[kimba325]

Hello everyone. My department is in the process of rewriting our SOP's which initiated a discussion amongst the examiners in our unit. A couple of questions were raised as to the difference in an erroneous exclusion and a missed identification.

1. The most recent SWGFAST document shows that an erroneous exclusion is considered a TYPE II error, but I have seen elsewhere that an erroneous exclusion is as serious an error as an erroneous identification. Would like to know what other labs have written these up as and why.

Also, what is the difference between an erroneous exclusion and a missed identification? (I have seen the SWGFAST definitions).

Is it as simple as:

Missed ID = Examiner concluded INC, although, there was sufficient detail to ID.
Erroneous EXC = Examiner concluded EXC, however, two impressions were from the same source.

Thanks for your time and help! I would hate to have written policy that not everyone truly understands.

Kim

[David Fairhurst]

I would say that erroneous exclusions are a subset of missed IDs.

A missed ID is exactly what it says on the tin, the ID was there and it didn't get reported.
This could be for the legitimate reason of the exemplars not being complete or of sufficient quality. If the examiner reports an incomplete/inconclusive-due-to-exemplars examination this is not an error on their part but a failure of quality control in the taking of exemplars.

However, a missed ID could be the result of the examiner simply not finding the ID.
It could be an inadequate AFIS search not leading to an ID that would have been picked up in a direct comparison. This could be attributed to system limitations, exemplar quality or operator inadequacies.
It could be that the examiner made an incorrect digit or palmar determination in his analysis of the latent and never looked at the right area on the exemplars. This is just a failure of the examiner to find the ID.
It could be that a neophyte examiner finds the corresponding area but it does not evaluate to an ID to them and never gets passed on for review, where it could be identified by the more proficient examiner.
I'm sure you can all think of lots more examples.

The only time a missed ID becomes an erroneous exclusion is when it is reported as an exclusion.
If the examiner fails to recognise the limitations of their examination (legitimate or otherwise) and reports...
"Fred Bloggs did not leave this latent print at the crime scene... SOMEONE ELSE DID"
That is both a missed ID and an erroneous exclusion.

[Tazman]

The problem that arisies from written policies is that they must be enforced. If you write strict consequences for all technical errors, then you must enforce your policies. If you make erroneous exclusions and missed identifications equal in seriousness to erroneous identifications in your policies, then you must punish your people equally for all three technical errors. And if you make all three technical errors equal, it will happen faster than you expect.

On the other hand, if you can figure out a good solution to this problem, post it here and fingerprint units all over the world will copy it and hail you as a savior. I don't know of any agency that has it right yet.