FORENSIC SINGLE FIBER DISCRIMINATION BY COMBINING EXCITATION-EMISSION FLUORESCENCE MICROSCOPY WITH LINEAR DISCRIMINANT ANALYSIS

A MUÑOZ DE LA PEÑA; A CAMPIGLIA,; N. MUJUMDAR; E. C. HEIDER; GOICOECHEA H C; DAVID MUNOZ DE LA PENA

Congreso; XVIII CAC 2016; 2016

The potential of total excitation-emission fluorescence microscopy combined with multi-way lineardiscriminat analysis (LDA) was investigated for the forensic analysis of visually indistinguishabletextile fibers. Forensic fiber comparison involves one questioned fiber (i.e the fiber found in the crimescene) versus one or more fibers (called ?known fibers?) collected from a textile of the same colorbelonging to a suspect. Our approach takes fluorescence microscopy to a higher level of selectivitywith the collection of excitation emission matrices (EEMs) [1, 2]. For that, four pairs of visuallyindistinguishable fibers from four different textiles were selected. The fibers consisted of nylon 361dyed with acid yellow 17 and acid yellow 23, acetate satin 105B dyed with disperse blue 3 and disperseblue 14, polyester 777 dyed with disperse red 1 and disperse red 19, and acrylic 864 dyed with basicgreen 1 and basic green 4, and were investigated using a non-destructive approach, which is ofparamount importance to preserve the physical integrity of the fibers for further court examination.Excitation emission matrices were recorded with the aid of an inverted microscope coupled via a