In an article posted over at the Armed Citizens' Legal Defense Network, the author, Marty Hayes, discusses the recent evidence dump from the Zimmerman Case in Florida.
In addition to the strengths and weaknesses of the case he mentions that the autopsy on Trayvon Martin found "soot and stippling" near the entry wound and what the implications of that might be.
There is more evidence adding to the validity of Zimmerman’s story. There was soot and stippling on Martin’s body at the wound’s entry point. This indicates a close gunshot. Some reports say 2 to 4 inches; some estimates extend the distance out to 16 inches.
At 2 to 4 inches it would be pretty clear that Zimmerman fired from nearly contact distance which is consistent with his story that Martim was beating on him when the fatal shot was fired. A 16 inch distance might be a little harder to defend because a prosecutor could argue that Martin was trying to disengage when he was shot.
How to settle it?
To firmly establish the likely distance the gun was from Martin’s chest, the defense needs to conduct ballistic tests with the gun, firing the same type of ammunition through a sweatshirt against a test surface to record the stippling pattern.
The lab will try to get samples of the ammunition from the same lot or, failing that, from a lot the manufacturer can certify as being identical. The ammunition will then be tested under conditions that simulate the alleged conditions and possible distances. From that, the actual distance the shot was fired at can be more accurately estimated.
What makes this testing possible is the existence of the careful records and the "exemplars" from each lot that some ammunition manufacturers keep. More importantly, these records are presumed to be unbiased. While the same kind of testing can be down on reloaded ammunition, it would be difficult to get it admitted into evidence precisely because the record are not unbiased. Even if it was admitted, the prosecution could argue to the jury that the handloads tested cannot be assured the same what was used in the actual shooting thereby casting doubt on any defense claims that rely on forensic data related to the ammunition used.
I know that the choice of what ammunition to carry is a contentious issue. The fervor in caliber wars approaches the religious and which brand and bullet type within a caliber are like unto interdenominational squabbles. The argument over carrying factory ammunition versus handloads is no less acrimonious.
If you choose to carry a gun for self defense I won't tell you what to carry or what kind of ammunition to use in it -- we each are entitled to our own mistakes. I do encourage you to remember that the thug you may have to shoot is a less dangerous and less implacable foe than a legal system that may want to make an example of you for political purposes.
H/T to Grant Cunningham at The Revolver Liberation Alliance