Houston Forensic Science Center Ruger LCP LEA scans
Email csafe@iastate.edu to obtain the data.
The data consist of
scans of bullet land engraved
areas in x3p format. The
study is structured so
that there are three test
kits (G1, G2, G3), each
containing sets of known
and unknown bullets. The kits
are based on a set
of ten consecutively rifled
Luger LCP barrels, labeled A
- J, with an additional
three nonconsecutively rifled barrels
(R1, R2, R3).
In each
test kit, there are three
test fires each from five
consecutively rifled barrels, as
well as ten questioned
bullets whose source is
unknown. This set is an
open set, so the questioned
bullets may have been fired
from weapons not included
in the test set, that
is, from R1-R3 instead of
A-J. Each bullet contains
6 land engraved areas,
which are identified as Land
1-Land 6. In total, each
test kit consists of 150
scans, for a total of
450 scans for all three
test kits.
The x3p format provides for the inclusion of relevant metadata within the x3p file, including the machine used to scan the bullets, the operator, and the resolution of the scan. The total dataset size is 4.5 GB.
Generally, files are grouped
as follows: SetGG/BarrelXX/BulletY/LandZ.x3p. Unknown bullets are stored in an Unknown folder within each set and are identified by U00, where 00 can be any two-digit number.
Information on x3p format: https://www.iso.org/standard/62310.html
We have produced two R packages meant to work with this data:
- x3ptools (on CRAN, with dev versions on github at heike/x3ptools). x3ptools contains utilities for reading, writing, annotating, rendering, and exporting x3p data to other formats.
- bulletxtrctr (dev version on github at heike/bulletxtrctr). bulletxtrctr contains utilities for extracting useful data from bullet LEA scans as well as a matching algorithm used to match unknown bullets to the barrels they were fired from.
Scans were created by the Roy J. Carver Microscopy Lab at Iowa State.
