longdayjake said:
Frank, you kinda proved my point. A California lawyer basing his opinion on his experience with California law....
In your profile you claim to be a law student. You really should know better.
The laws of evidence are pretty much the same in every jurisdiction. And in the course of my career I had occasion to deal with the laws of many States. Furthermore, I have studied use of force and related law in many States.
In addition, other lawyers who have been involved in these threads here on THR and over at TFL, notably Spats McGee and Bartholomew Roberts, have been in agreement with me. Spats McGee practices in Arkansas. Bartholomew Roberts practices principally in Texas and is also, I believe, licensed in Oklahoma.
I practiced law for over thirty years. How long have you practiced law?
Sam1911 said:
...I think one of the major points of (educated) contention as that thread developed was that GSR is not such a cartridge-specific phenomenon that there would be any sound reason to not admit GSR evidence produced by similar (or almost ANY) handgun ammunition tested by an impartial lab such as the state's own forensic lab....
Actually no.The only people making that claim have been non-lawyers, who apparently don't understand the business of actually getting things into evidence in court. The lawyers, me, Spats McGee and Bartholomew Roberts, when addressing this issue both here and on TFL (where it has also come up often) have been agreed on the inadmissibility of expert opinion based on GSR testing when handloads have been used.
The basic rule of evidence regarding the admissibility of expert opinion based on a scientific test is that it has to be relevant. In order to be relevant, a sufficient nexus between the test and the subject matter of the litigation must be shown -- in other words, the thing tested must be established to the satisfaction of the judge to be the same as the thing at issue in the litigation.
If the thing tested is a cartridge, the party submitting the opinion based on the test has to show that the cartridge fired in the test was the same as the cartridge fired in the incident that is the subject of the litigation. When handloads were used, the only way to connect the cartridge tested to the cartridge fired in the incident is the defendant's claim. That is inherently suspect and will not support a legally acceptable foundation for the introduction of the opinion based on the test.
If identifiable factory ammunition was involved, the manufacturer is a disinterested third party, and evidence from the manufacturer, such as quality control protocols, can be used to establish the comparability of the test cartridges and the incident cartridge.