关键词: 微量物证, 法庭地质学, X射线荧光光谱, 高空坠物

Abstract: Objective To establish a comprehensive method for comparing bricks from the scene and suspicious sources, and tracing the source of the questioned falling brick. Methods X-ray fluorescence spectrometry （XRF）, X-ray diffraction （XRD） and scanning electron microscope-energy dispersive spectrometry （SEM/EDS） methods were used to study the differences in appearance, minerals and elements of the questioned falling brick and eleven known bricks. Range analysis was applied to the quantitative XRF data of different brick samples. Results Known samples collected from six suspicious rooms were excluded as significant difference was observed in the analytical results. The room where the known sample 8-11 were collected from was recognized as the source of the falling brick, for the examination revealed no significant difference. Conclusion The elemental and mineralogical analysis results of the bricks and the concrete residues helped to distinguish different bricks and confirm the source of the questioned brick. By multi-method analysis and statistical data process, brick samples can be compared and their falling source might be detected, which provides forensic evidence for the investigation of falling objects cases.

Key words: trace evidence, forensic geology, X- ray fluorescence spectrometry, falling object