Circa 1846 Daguerreotype – Alexander Joy Cartwright debate

[benjulmag]

Originally Posted by bmarlowe1

>>As to methodology, Mr. Mancusi's belief that individual comparison of each of the A Subjects to Subject C is not necessary, that one can apply the Subject C to Subject A4 comparison conclusion to a Subject C to Subject A1, A2 or A3 comparison, is simply incorrect.

No that is not correct and you have said nothing to support that other than to repeat it. My response is on p. 28:
Mr. Richards states, “each ‘known’ image should be independently compared with the questioned image.” He asserts that it is necessary to not only compare A4 directly to C, but to also individually compare A1, A2, and A3 to C. But he does not state what difference he thinks that would make - what features of A1, A2 or A3 would compare more favorably to C? All the A's have virtually the same forehead width, so it suffices to then compare only one of them directly to C. The same can be said for the particular characteristics of the eyelid, lips/philtrum, and nose.

When you want to measure something, you don't have to go to the National Bureau of Standards to get "the" ruler. Any ruler from Walgreens will do just fine. That's because we know that the Walgreens ruler is sufficiently close to the NBS ruler to do the job.[FONT=Verdana][SIZE=2]

From page 34 of the newsletter supplement:

And, of most concern, his report shows no recognition that the conclusions one draws when comparing Subject C to Subject A4 are not necessarily the same as the conclusions one can draw when individually comparing Subject C to Subjects A1, A2, A3 or A4 regardless whether one concludes that Subjects A1, A2, A3 and A4 are the same individual.

This last point is crucial and warrants further explanation. When a person poses, no two poses are precisely the same, especially if they are taken in different photo shoots. A person may tilt his head one way one time, another way the other time. He may be in a better mood and therefore exhibit a different smile. The studio lighting could be different. He could have suffered a disfiguring injury. The reasons are endless. If there are no exclusionary differences between the comparison subjects, the conclusion that the subjects likely are different individuals then becomes a subjective determination that relies crucially on how one’s brain interprets the comparison of the two subject images. So, say, if I was to regard it as a close call between concluding that the subjects possibly could be the same individual versus concluding they likely are not, there could easily be enough differences in the subject’s appearance in another pose to cause my brain to perceive the second comparison just differently enough that I will arrive at the other conclusion. This is accepted doctrine in photo ID, as Mr. Richards states, and is consistent with simple common sense. There are no shortcut methods to doing photo ID. If Mr. Mancusi desires to opine whether Subject C is the same person as Subjects A1, A2 and A3, he must undertake separate comparisons with those other subjects. He failed to do so and therefore his conclusion that Subject C is unlikely to be one of the other A subjects is necessarily suspect due to having been derived through improper analysis.

This response pertains to the "art" component inherent in photographic facial ID.