Commercial software Carburane, developed at the IFP Energies Nouvelles, was originally designed to accurately evaluate petroleum fraction quality. It can also be applied to forensic problems, and in particular to arson investigation. During a 15-month period, about 350 premium gasoline samples, representative of the three types available on the French territory (SP95, SP95-E10, SP98), were obtained from different oil companies and their associated distribution networks. Samples were collected in gas stations, placed in sealed containers, securely packaged, and were next analysed in the IRCGN laboratory by high resolution capillary column GC (gas chromatography) with flame ionisation detection for the separation and characterisation of different hydrocarbon families. Data processing using Carburane software provided accurate characterisation and comparison of premium gasoline samples that could have been used as fire accelerants. It could assess the closeness of unburned premium gasoline samples found at a crime scene, with similar samples from gas stations or from searched suspect premises. Application to the real case study of a burned residential house provided useful information to the investigators.

An analytical method was developed to characterize puparia cuticular lipids (hydrocarbons, waxes) and to compare the molecular distribution patterns in the extracts from either recent or older puparia. Acid-catalyzed transesterification and solvent extraction and purification, followed by combined gas chromatography coupled to mass spectrometry, were optimized for the determination of hydrocarbons and fatty acid ethyl esters from transesterified waxes, extracted from a single species of a fly scavenger (Hydrotaea aenescens Wiedemann, 1830). Comparison between recent (2012) or older (1997) puparia contents has highlighted significant composition differences, in particular, a general decrease of the chain length in the n-alkane distribution pattern and, on the contrary, an increase of the ester chain length. Both extracts contain traces of three hopane hydrocarbon congeners. Preliminary results evidence the change in puparia lipid composition over time, thus potentially providing new indices for estimating postmortem interval.

Does this gun shoot?When firearms are found on a crime scene, investigators frequently sniff the canon aperture in order to identify which of them could have been used recently. This technique gives useful information but is not based on a scientific and validated methodology. In order to solve this problem, the French Gendarmerie Forensic Research Institute has developed and validated an analytical method based on extraction of aromatic hydrocarbon residues by solid phase micro-extraction (SPME), followed by gas chromatography coupled with mass spectrometry (GC/MS).

Stable isotopes for forensic science and justice The relative abundance of certain stable isotope constituents of the material is a considerable information source and behaves as a memory of the origins (synthesis or biosynthesis) and transformation of the material. This "signature" then can be run in the process of inference of the origin of a common source in scientific police. In certain cases, it constitutes a legal method of identification.

Analysis of tear gases traces from self-defence devicesIn certain types of criminal investigation, it is sometimes necessary to search for traces of lachrymatory substances, such as those found in self-defence devices readily available in many retail outlets. The presence, or absence, of such substances may be important evidence and, as such, may have a significant impact on the progress of the investigation. Recently developed chromatographic methods combined with mass spectrometry using different modes of ionisation, including electron impact (El), atmospheric pressure chemical ionisation (APCI) and tandem mass spectrometry analysers (MS/MS), are effective for detecting trace levels of lachrymatory molecules, including 2-chlorobenzylidene-malonitrile (CS), capsaicin and its analogues that have been synthesized or are present in oleoresin Capsicum extracts.