Journal Published Online: 01 September 2002
Volume 47, Issue 5

Evaluation of Exhibits from a Murder Case Using the Lead Isotope Method and Scanning Electron Microscopy



We have used a combination of lead isotopes and scanning electron microscopy to determine the relationships between different exhibits in a murder case. Samples involved lead projectiles removed from the deceased's head and a pillow, lead-rich scrapings and particles (gunshot residues) from spent cartridges and a silencer, and particles from a pillowcase. The lead projectiles had the same isotopic composition. with the lead being derived from the same dominantly geologically old source(s). The lead smear from the silencer had the same isotopic composition as the projectiles, and the lead was probably from the same source. The particles from the spent cartridges had varying elemental compositions ranging from PbO to PbCuZn ± Ba with or without Si and are consistent with derivation from the primer. The lead isotopic compositions of the particles from the spent cartridges show some variations, but these are markedly different from those of the projectiles, indicating lead from a mixture of geologically old and geologically young lead. The particles from the pillowcase were extremely small (usually ≮50 μm size) and showed varying isotopic compositions, some consistent with the gunshot residue from the cartridges. As the exhibits had been handled extensively prior to the present investigation, including some being sent to North America, there is a high likelihood that handling was not done in clean room environments and may have been contaminated. In this instance, as we were concerned about contamination, especially of the pillowcase, we felt contamination negated use of the results for assistance in proving the innocence or guilt of the accused. A combination of high-precision lead isotope measurements with scanning electron microscopy provides a powerful tool for forensic investigations if precautions are taken in handling the exhibits.

Author Information

Gulson, B
CSIRO/DEM, North Ryde, NSW, Australia
Eames, JC
LQMA Pty Ltd, Castle Hill, New South Wales, Australia
Davis, JD
CSIRO/DEM, North Ryde, New South Wales, Australia
Pages: 7
Price: $25.00
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Stock #: JFS15508J
ISSN: 0022-1198
DOI: 10.1520/JFS15508J