Forensics aim to prove how Phillip Peatross was shot | Forensic Files

this is where we are going to do the test firing um to get our distance tests where we're we're going to fire our
suspect firearm um using both suspect ammunition and laboratory ammunition for comparison and we're going to fire into
our test fabric at known distances what's the difference between suspect ammunition and lab ammunition there was
ammunition that was emitted with the suspect revolver um so this is ammunition that was actually uh removed
from the cylinder of the revolver at the time we need to test fire laboratory ammunition along with the suspect
ammunition because the ammunition that's used has a great effect on the residues
that are left on the surface so it's a reproducibility we don't have a lot of ammunition from the scene we have a lot
of lab ammunition so we want to make sure although we've gotten the same type of ammunition we want to look at the
reproducibility of our ammunition uh to the suspects this particular revolver is
not the one that was collected for evidence when we did the actual testing it was indeed the revolver that was uh
submitted by the law enforcement agency that was collected at the time this is actually a firearm from our laboratory
collection we keep a Firearms reference collection and where they're from is they're actually from actual cases
through throughout many years once the the the criminal case has been finished um many of those Firearms will actually
end up being destroyed you really want to try to limit your variabilities that's why you want to make sure that
there is reproducibility between uh the same ammo uh that we're using and that the suspect has that's why we use the
same gun the what we can't reproduce is skin so there's clear variability between twill and Skin So
you want to reduce every other variability so you'll be firing into the twi how far away at the time that we did
the test we used the actual evidence revolver and we used both evidence ammunition which we had a limited supply
of and we fired tests at 1 in 3 in 6 in 12 in and 18 in you shoot you look at the pattern and
you want to get the two brackets so it's definitely greater than and the larger one out definitely less than and uh
that's what we looked for first so the 1 in and 18in it was definitely within those
we don't know exactly um how skin reacts compared to the white cotton twill so therefore we're we're developing a
conservative bracket and we're looking for those end brackets that are obviously different than what the
pattern was in the skin how accurate is this test I think it's has a range it's not going to be one to one it helps you
it's a tool just like anything else it's a tool it's not an answer uh per se that's why we have to give a bracket uh
it is accepted uh scientific working group accepted this methodology for giving a rough um Range

To determine if Philip Peatross' death was a suicide or homicide, Orlando Chief Medical Examiner Dr. Jan Garavaglia and forensic scientist Matt Conway need to know the distance the gun barrel was from Peatross' face. In this demonstration for "48 Hours", they explain how gun tests are conducted to determine that distance.

Brief Summary

Test firing firearms with suspect and lab ammunition highlights reproducibility and material variability.

Key points

Testing Firearms for Evidence. We're testing both suspect and lab ammunition to compare residues left on fabric.

Episode highlights

Testing Firearms for EvidenceWe're testing both suspect and lab ammunition to compare residues left on fabric.“We want to make sure that there is reproducibility.”1:46Apr 6, 2014

Episode quotes

It's a tool, not an answer.

3:39WatchApr 6, 2014

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