INTRODUCTION Questioned document is defined as documents suspected of being fraudulent or whose source, history and authenticity are dubious. Questioned documents are normally associated with criminal activities such as fraud, forgery, blackmailing, illicit drugs trafficking and homicide therefore proper and systematic analyses of such documents may help in solving the crimes related to the documents. Ballpoint pens are perhaps the most popular writing implements and are widely used thus it is not surprising to see their association with fraud and criminal cases. Ink analysis is one of the important aspects in questioned documents examinations to determine the authenticity or validity of a document. Therefore it is extremely imperative to have accurate and discriminating ink analyses protocol. One of the instrumental techniques commonly employed for forensic ink analysis is Fourier Transform Infrared (FTIR) spectroscopy. Recent development of the Attenuated Total Reflectance (ATR) has revolutionised forensic ink analysis by providing a simple, rapid, non-destructive and cost effective analytical approach (Reed et al., 2011). Statistical technique of Pearson Moment Correlation (PPMC) and chemometrics technique of Principal Component Analysis (PCA) especially the score plot can be used to “display” the relationship between objects. OBJECTIVES OF THE STUDY 1. 1.To analyse unbranded black ballpoint pen inks using FTIR spectroscopy To analyse the spectra obtained from the FTIR of the unbranded black ballpoint pen inks using PPMC and PCA To evaluate the abilities of FTIR spectroscopy as well as PPMC and PCA for source determination of an unknown ink from a simulated threatening note. METHODOLOGY Eleven (11) unbranded black ballpoint pens (designated as pen A, B, C, D, E, F, G, H, I, J and K) collected during an education fair in May 2013 from 11 universities participating in the fair were used in this study. Ink line of each pen was prepared on white A4 paper and then analysed using FTIR. One of the pens i.e. pen collected from the University Malaysia Terengganu (UMT) (reference code: B) was used to write a simulated threatening note. The FTIR spectra of each ink including the unknown ink were examined manually by direct visual examination prior to PPMC and PCA. Figure 2 :Score Plot of PC1 vs. PC2 Principal component analysis (PCA) was performed to the entire data points available in the FTIR spectra of the unbranded ballpoint pen inks including the unknown. Figure 2 shows the score plot of the first two principal components i.e. PC1 and PC2 where five clusters are apparent. It is interesting to note that the unknown is positioned quite close to pen B. Referring to the PC scores, pen B has PC1 = 0.42, PC2 = whilst the unknown (designated as U) has PC PC1 = 0.44, PC2 = Since there are no any other points positioned quite close to the unknown, therefore on the basis of the PC sores, it could be said that the unknown (U) could have originated or could have been written using pen B. In actual fact (priori knowledge), the simulated threatening note was written using pen B (UMT).. RESULT AND DISSCUSSION Figure 1 shows the FTIR spectrum of the unknown ink. Based on direct visual examination of the unknown ink against the 11 unbranded ballpoint pen inks, the simulated threatening note could have been written using pen B, E or H. All in all, direct visual examinations of the FTIR spectra were not able to determine the actual source of the unknown ink, in other words, had failed to give conclusive outcomes. PPMC helps in revealing relationship or correlation between two objects. The degree of fit between two objects of interest is given in term of Pearson’s correlation coefficient i.e. r where value approaching unity indicates strong relationship and vice-versa. Table 1 displays the r value of the 11 unbranded ballpoint pen inks computed against the unknown. From the table, high r values are given by almost all inks except ink from pen A (r = 0.879). It is interesting to note that, combination of ink from pen B and the unknown gives r = Based on the idea suggested earlier, the unknown could have originated from ink of pen B however due to the closeness of r of other ink combinations with the unknown, it is quite impossible to conclusively determine the actual source of the unknown ink using PPMC. CONCLUSION LITERATURES CITED Ali Raza, & Saha, B. (2013). Application of Raman spectroscopy in forensic investigation of questioned documents involving stamp inks Andermann, T. (2011). Raman Spectroscopy Of Ink On Daniela Laura Feraru, Aurelia Meghea, & Badea., N. (2013). Forensic Discrimination of Ballpoint Pen Inks Based on Correlation of Data Obtained by Optical and Spectral Methods Antonio de Oliveira Mendes, Paulo Torrao Fiadeiro, Ana Maria Matos Ramos, & Sousa., S. C. L. d. (2013). Development of an optical system for analysis of the ink–paper interaction. 24, 1733–1750. Xiang-Feng Wanga, Jing Yub, Ai-Lan Zhang a, Dai-Wei Zhoua, & Meng-Xia Xie a. (2012). Nondestructive identification for red ink entries of seals by Raman and Fourier transform infrared spectrometry Nikolaos D. Kalantzis, B., MFSSoc. (2013). Paper interference in ink Raman spectra at 685nm: A preliminary report Marek Hoehse, Andrea Paul, Igor Gornushkin, & Panne., U. (2012). Multivariate classification of pigments and inks using combined Raman spectroscopy and LIBS Kunicki, M. (2002). Differentiating Blue Ballpoint Pen Inks Emma WAGNER, & CLEMENT, S. (2001). Surface Enhanced Resonance Raman Scattering (SERRS) spectroscopy Study on Inks PRINCIPAL COMPONENT ANALYSIS (PCA) FOR OBJECTIVE COMPARISON AND SOURCE DETERMINATION OF UNBRANDED BLACK BALLPOINT PEN INKS Muhammad Naeim Mohamad Asri* MSc, Nor Hafizah Hashim BSc, Wan Nur Syuhaila Mat Desa PhD, Dzulkiflee Ismail PhD Forensic Science Programme, School of Health Sciences, Universiti Sains Malaysia, Health Campus, Kubang Kerian, Kelantan, Malaysia. * Corresponding Author The authors would like to acknowledge USM for funding this work under the Short Term Research Grant Scheme (304/PPSK/ ) and Jabatan Perkhidmatan Awam (JPA) for the research studentship awarded to M.N.Mohamad Asri. Special thanks to Mr.Baharuddin Zakaria for helping us out with FTIR-ATR analyses. ACKNOWLEDGEMENT PEN r A0.879 B0.999 C0.990 D0.917 E0.987 F0.951 G0.943 H0.966 I0.963 J0.928 K0.937 Figure 1: The FTIR spectrum of the unknown Of the examinations conducted in this study, the PCA (through examinations of its principal component scores) have successfully linked the unknown ink to pen B which was the actual source. The findings of this study indicate the potential of combining spectroscopic technique with statistical and chemometrics techniques for source determination of unbranded ballpoint pen inks. Presented at the National Forensic Science Symposium (NFSS), Petaling Jaya, th March 2015