But if instead of an open “are guns noxious?”, someone’s starting point is “guns are noxious, now how do we stop that?”, this starts to make a lot more sense. Now technical details become dangerous, not helpful. The foundational premise is that guns are noxious. So it would be game theoretically stupid to learn about them, because that knowledge can only cut against your premise. So a rational actor would acquire only enough technical knowledge to sound convincing to the laity, and no more.
I am a firearms examiner, and have been for the last four years.
The field is completely sound, despite what the article you based yours off of might say.
Firearms examiners base their examinations on the fact that no two tools will be created the same way, and share the same wear patterns. There are thousands of studies that demonstrate that items made one after another display differences due to tool wear, which are imparted onto expended bullets and casings and can be used to differentiate between sources.
It takes years of training and study to be able to make identifications, so the slew of statisticians and non-forensic analysts who try to publish articles without understanding the science are extremely incorrect regarding the scientific foundation.
That's fair. I wouldn't dispute that the field has merit. The specific aspects apart from that that I'd question are whether (a) the evidence is as airtight as believed when presented in court (or whether in certain instances there's nuance and uncertainty there that juries aren't educated on), and (b) whether courts are institutionally good at scientific rigor (would argue that they're not).
(A) I can't speak for every lab, nor for every training program, but I know that my training has been extremely thorough and incorporates a ton of scientific literature, manufacturing literature (and touring facilities), and hands-on experience. If I render an identification (a same-source) conclusion on a microscopic comparison, it means that I am 100% confident that the two items are from the same source. A second examiner then reviews the evidence, and has to come to the same conclusion, before the report is issued. The error rate of positive identifications, according to a large amount of studies, is within the acceptable standard of <5%. And with two examiner reviewing the evidence, we as a lab are pretty confident in our results. If we are at all not sure of the results, we move to an inconclusive answer, which means we can't say if the two items originate from the same source. And if we notice that they are so different that they can't be from the same source, we provide an elimination. But what really matters in the eyes of the law are the identifications; those results are what are used to push for a conviction. So we do everything we can to make sure those results are as correct as can be.
However, I restate that this is how my lab handles it and other laboratories or examiners may be less comprehensive or ethical.
(B) The judge acts as a gate-keeper for the evidence, and is susceptible to their own biases as well as the presentations during evidentiary hearings. The court system has its own flaws, which my field has to face constantly, however I feel it drives the field forward having to constantly prove itself reliable. Because of recent doubts by several important reports (recent being the last 20 years), a slew of studies have been developed that support the scientific foundation of firearms identification.
Regarding presenting the evidence to a "jury of your peers," it becomes my job to present my results clearly and in a way that can be easily understood, and after that it is in the hands of the jury, who may misunderstand or misattribute the importance of the scientific evidence. That can't be helped by me, but is a problem with the court system that other factors then try to mitigate.
Well said:
"""
But if instead of an open “are guns noxious?”, someone’s starting point is “guns are noxious, now how do we stop that?”, this starts to make a lot more sense. Now technical details become dangerous, not helpful. The foundational premise is that guns are noxious. So it would be game theoretically stupid to learn about them, because that knowledge can only cut against your premise. So a rational actor would acquire only enough technical knowledge to sound convincing to the laity, and no more.
"""
Glad to see Base Rate Neglect here.
It was brought up to good effect in Mr. Correia's book and no less effective here.
Greetings
I am a firearms examiner, and have been for the last four years.
The field is completely sound, despite what the article you based yours off of might say.
Firearms examiners base their examinations on the fact that no two tools will be created the same way, and share the same wear patterns. There are thousands of studies that demonstrate that items made one after another display differences due to tool wear, which are imparted onto expended bullets and casings and can be used to differentiate between sources.
It takes years of training and study to be able to make identifications, so the slew of statisticians and non-forensic analysts who try to publish articles without understanding the science are extremely incorrect regarding the scientific foundation.
That's fair. I wouldn't dispute that the field has merit. The specific aspects apart from that that I'd question are whether (a) the evidence is as airtight as believed when presented in court (or whether in certain instances there's nuance and uncertainty there that juries aren't educated on), and (b) whether courts are institutionally good at scientific rigor (would argue that they're not).
It's probably easiest to respond in parts:
(A) I can't speak for every lab, nor for every training program, but I know that my training has been extremely thorough and incorporates a ton of scientific literature, manufacturing literature (and touring facilities), and hands-on experience. If I render an identification (a same-source) conclusion on a microscopic comparison, it means that I am 100% confident that the two items are from the same source. A second examiner then reviews the evidence, and has to come to the same conclusion, before the report is issued. The error rate of positive identifications, according to a large amount of studies, is within the acceptable standard of <5%. And with two examiner reviewing the evidence, we as a lab are pretty confident in our results. If we are at all not sure of the results, we move to an inconclusive answer, which means we can't say if the two items originate from the same source. And if we notice that they are so different that they can't be from the same source, we provide an elimination. But what really matters in the eyes of the law are the identifications; those results are what are used to push for a conviction. So we do everything we can to make sure those results are as correct as can be.
However, I restate that this is how my lab handles it and other laboratories or examiners may be less comprehensive or ethical.
(B) The judge acts as a gate-keeper for the evidence, and is susceptible to their own biases as well as the presentations during evidentiary hearings. The court system has its own flaws, which my field has to face constantly, however I feel it drives the field forward having to constantly prove itself reliable. Because of recent doubts by several important reports (recent being the last 20 years), a slew of studies have been developed that support the scientific foundation of firearms identification.
Regarding presenting the evidence to a "jury of your peers," it becomes my job to present my results clearly and in a way that can be easily understood, and after that it is in the hands of the jury, who may misunderstand or misattribute the importance of the scientific evidence. That can't be helped by me, but is a problem with the court system that other factors then try to mitigate.
Makes sense, thanks.