Large area imaging of forensic evidence with MA-XRF

Abstract

This study introduces the use of macroscopic X-ray fluorescence (MA-XRF) for the detection, classification and imaging of forensic traces over large object areas such as entire pieces of clothing and wall paneling. MA-XRF was sufficiently sensitive and selective to detect human biological traces like blood, semen, saliva, sweat and urine on fabric on the basis of Fe, Zn, K, Cl and Ca elemental signatures. With MA-XRF a new chemical contrast is introduced for human stain detection and this can provide a valuable alternative when the evidence item is challenging for conventional techniques. MA-XRF was also successfully employed for the chemical imaging and classification of gunshot residues (GSR). The full and non-invasive elemental mapping (Pb, Ba, Sr, K and Cl) of intact pieces of clothing allows for a detailed shooting incident reconstruction linking firearms and ammunition to point of impact and providing information on the shooting angle. In high resolution mode MA-XRF can even be used to provide information on the shooting order of different ammunition types. Finally, by using the surface penetration of X-rays we demonstrate that the lead signature of a bullet impact can be easily detected even if covered by multiple layers of wall paint or human blood.

Review of in vivo optical molecular imaging and sensing from x-ray excitation

“…Tissue sensing and imaging nearly necessitate the use of monoenergetic gamma rays or synchrotron x-ray sources to suppress the non-specific background and achieve higher signal to noise. 16,17 The strength of the synchrotron approach is that the background is low and most of the stronger emission lines are clearly separated from one another.…”

More than XRF Mapping: STEAM (Statistically Tailored Elemental Angle Mapper) a Pioneering Analysis Protocol for Pigment Studies

“…The location of the acquisition points ( Figure 2 and left zoom in Figure 1) has been chosen by art historians on the basis of the available documentation about the conservation history of the painting. Cinnabar (tempera) Red Ocrhe (tempera) (8) Red Lake (tempera) (9) Cinnabar (tempera) (10) Red Ocrhe (tempera) (11) Hematite (tempera) (12) Cinnabar (tempera) Red Lake (tempera) (13) Red Ocrhe (tempera) Red Lake (tempera) 14Cinnabar with White Lead (tempera) (15) Cinnabar, Red Lake with White Lead (tempera) Red Lake (tempera) (16) Hematite with White Lead (tempera) Red Lake (tempera) 17Cinnabar, Red Lake with White Lead (oil) Red Lake (oil) 18Red Lake, Cinnabar with White Lead (tempera) (19) Verderame, Yellow Lead, Red Lake with White Lead (tempera) Red Lake (tempera) (20)…”

“…Green dress 1Right Angels Blue dress 2Right Angels Face of the green dressed 3Right Angels Hair of the green dressed 4Right Angels Halo of the green dressed 5Right Angels Sleeve of the green dressed 6Right Angels Red dress 7Right Angels Hair of the blue dressed (8) Left Angels Green dress 9Left Angels Blue dress (10) Left Angels Sleeve of the bleu dressed (11) Left Angels Red dress (12) Left Angels Face of the red dressed 13Book Black Ink 14Book White of the pages 15Book Red ink (16) God the Father Yellow dress (17) God the Father Blue hat I (18) God the Father Blue hat II (19) God the Father Pupil 20God the father Iris 21God the Father Sclera 22God the Father Face (23)…”

Comparative analysis of the dust retention capacity and leaf microstructure of 11 Sophora japonica clones

“…XRF has many advantages over the traditional atomic absorption method, such as the ability to use smaller samples, the shorter analysis time, the ability to examine a wide range of analytical elements, its high accuracy and lesser sensitivity to experimental errors, and its low risk coefficients. It has been used widely in biology, medicine, criminal investigations, and other fields [ 19 – 21 ], but it has not been applied in forestry or horticulture.…”