Tire Classification by Elemental Signatures Using Laser-Induced Breakdown Spectroscopy

Abstract

Tire evidence is a form of trace evidence that is often overlooked in today's forensics, while frequently found at crime or accident scenes, usually in the form of skid marks. The pattern of the tire skid mark has been used before to link a tire or car to a scene, but the widespread use of anti-lock braking systems makes this an almost impossible and abandoned route of analysis. With this is mind, using the chemical profile of a tire has potential to link a car or tire back to a scene in which its trace material is found. This study shows the successful use of the elemental profile of tire rubber to classify thirty-two different samples by Laser-Induced Breakdown Spectroscopy (LIBS), analyzed by Principal Component Analysis (PCA) combined with Linear Discriminant Analysis (LDA). A classification accuracy close to 99% shows the ever-growing use of LIBS as a technique of choice for forensic analysis of tire rubber, opening the path for its use as a forensic evidence.

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…There are two forensic applications of polymer analysis. 122,123 These are discussed in more detail in the forensic section and will therefore not be discussed further here. The reader is referred to Section 5.2 for more details for these papers.…”

“…However, Lucchi et al have used LIBS to analyse tyres followed by chemometric analysis of the data (PCA combined with linear discriminant analysis ) to classify tyres. 122 A total of 34 tyre samples (32 individual tyres, one of which was sampled in triplicate) were used for the study. Samples were analysed using the LIBS system operating at a power of 17 mJ and producing a 100 μm crater per spot.…”

Online identification and classification of Gannan navel oranges with Cu contamination by LIBS with IGA-optimized SVM

“…In recent years, in order to distinguish samples of high similarity using LIBS, chemometrics methods such as articial neural network (ANN), [21][22][23] support vector machine (SVM), 24,25 principal component analysis (PCA), [26][27][28] and partial least squares (PLS) 29,30 methods have been used to improve discrimination performance. Chemometrics is a chemical subdiscipline of multi-interdisciplinary methods, and offers advantages in data processing, signal analysis, and pattern recognition.…”

Correction of moisture interference in laser-induced breakdown spectroscopy detection of coal by combining neural networks and random spectral attenuation

“…Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectrometry technique with many advantages such as no or less sample pretreatment, simultaneous multi-element analysis, almost non-destructive detection, and online in situ analysis. 5,6 LIBS has been applied in medicine, [7][8][9] agriculture, 10,11 criminal investigation, [12][13][14] archeology, [15][16][17] and coal analysis. [18][19][20] Unfortunately, its accuracy would be decreased due to matrix differences.…”