We received this email last June:
Hello all,
The uniqueness of the firing pin design in Springfield Armory’s XDS pistol has been the subject of much discussion lately. Especially in regards to how the firing pin shape should be classified when creating cartridge case exhibits in IBIS. The message bellow clarifies Forensic Technology’s position regarding this particular firing pin and also provides our reasoning behind our decision.
Here are some sample images to keep in mind during the explanation… (Also provided as an attachment.)
Forensic Technology’s position on XDS cartridge case exhibits is that they should be entered as Firing Pin Shape: Rectangle. The reasons for this are as follows:
•Despite a similarly elliptical firing pin impression XDS cartridge cases are easily distinguishable from Glocks by the following traits: o No "Glock Type" rectangular flow-back on the surface of the breech face.
o The XDS has a massive drag mark due to the width of the elliptical firing pin.
o With their drag marks aligned, the XDS firing pin impression is 90 degrees different than that of a Glock's.
•Within the Rectangle Firing Pin Shape family the thin, elliptical FP impression of the XDS will stand out easily to both the IBIS correlation algorithm and the user’s eyes as completely different than all the other “SWD-Type” Rectangular entries. This means that even though they’re in the same family they should appear at the opposite ends of the spectrum when correlation results are reviewed.
•If you were to group them with the Glock Firing Pin Shape your breech face scores should be different enough but, because the FP correlation is rotationally invariant, and because both XDS and Glock FPs are similarly elliptical, you will ultimately end up with constant false positives within every FP correlation amongst Glock exhibits.
For these reasons we feel that Firing Pin Shape: Rectangle is the most viable overall option.
We also currently have our R&D Group working with sample sets of XDS exhibits in order to determine what the optimal red firing pin ring placement should be for both the breech face and firing pin impressions. When a conclusion has been reached Forensic Technology will release an acquisition protocol specific for XDS acquisitions. In the meantime, the red firing pin ring should be placed in a manner similar to Glocks, where the circle touches the four edges of the elliptical impression for both the Breech Face and Firing Pin acquisitions.
It is also strongly recommended that you flag cases that include XDS exhibits by entering ‘XDS’ in the High Profile case data field. Doing so will allow you to quickly identify and revisit these cases and exhibits in order to modify the red ring position once the above-mentioned ring placement protocol has been established.
In regards to the exhibit's orientation during acquisition, it should absolutely follow the standard protocols of:
•Drag mark towards 3 o'clock
•Ejector mark in the Northern Hemisphere
•Extractor mark in the Southern Hemisphere
•Parallel lines horizontal
The side-lit XDS image above shows the optimal orientation for breech face and firing pin acquisitions.
If you have any questions please feel free to contact Forensic Technology’s Global Customer Service. This will allow us to manage all enquiries uniformly and ensure we keep everyone on the same page.
All the best,
-Andy
Andrew Boyle
INTL. FIREARM FORENSICS SOLUTIONS MANAGER
FORENSIC TECHNOLOGY WAI INC.
Tel. Office +1.514.485.5618
Tel. Mobile +1.514.770.1917
www.forensictechnology.com