This article provides a very brief introduction to the methods used to collect, extract, concentrate, and analyze samples recovered from fire scenes where the use of an ignitable liquid is suspected. This article does not include interpretation of the analytical results derived from fire debris samples, which is dealt with elsewhere. There is much literature on this subject and only the significant reference books have been referred to. This article is an update on the previous version which was co-authored by E. Stauffer Commissariat d′Identification Judiciaire, Police Cantonale Fribourg, Fribourg, Switzerland.</p