Fibres are important trace evidence that can be found during the course of crime scene investigation. The identification and analysis of these fibres shed light as to the circumstances surrounding a particular crime. Identifying the factors that affect the transference of fibres under various environments are crucial in providing robust conclusions of a case per se, as highlighted in this work. Donor garments were made up of four different types of fibre; 100% cotton, 100% nylon, 100% polyester and 100% wool, that were used to observe the differences in the number of transferred fibres to the recipient garment (100% cotton) and vice versa with increasing contact times of 30, 60, 180, and 300 seconds respectively. To simulate contact between the donor garment worn by a suspect and the recipient garment worn by a victim in real-life situations, the donor garment was placed on top of the recipient garment which was laid on a piece of plywood. The numbers of transferred fibres, both from the donor to the recipient garment and from the recipient to the donor garment were observed and tested using microscopic examination, burning test, solubility test and dye extractability test. Results indicated that different types of garments transferred different number of fibres with increasing contact times, and the identification of the fibres are possible via the different tests applied in this work.

Wood is one of the most common material found in homes and industrial fires, particularly in Malaysia. The abundance of different types of wood used to build structures, frames, furniture and others are important to take note as wood is a conducive material that can be used to initiate and propagate a fire, particularly in forensic fire cases. This study was conducted to provide the volatile chemical fingerprint of burnt Merbau (Intsia sp.) wood using gas chromatographymass spectrometry (GC-MS). The wood samples were prepared under two conditions; fully dried and partially dried. Six study replications of each condition were burnt outdoors and underwent an extraction process using activated carbon tablets. The tablets were incubated in an oven for 16 hours at 80ºC. Next, the tablets were desorbed in two different types of solvent; pentane and ethanol. The pentane- and ethanol-desorbed volatile products were then introduced into the GC-MS. Volatile organic compounds obtained across both conditions were in the range of volatile acids, aromatics and its derivatives, D-glucopyranose, phenolic derivatives and cycloalkane. The compounds emitted by fully and partially dried Merbau wood samples were similar, differing only in the absence of malonic acid and succinic acid in partially dried Merbau wood samples. Both solvents desorbed different types of volatile compounds. The burning behaviour of partially dried Merbau wood were different to those documented from fully dried Merbau wood and is attributed to the composition of wood rather than the dry or wet conditions.

Lip print is useful in forensic investigations for individual identification. The present study aimed to discriminate sex based on lip print patterns in Malaysian Malay population in Klang Valley using a scanning technique. Lip prints of 360 subjects (180 males and 180 females) were taken using the lipstick-cellophane tape technique, pasted onto A4 papers. These papers were then scanned using Brother DCP-J100 printer (300dpi resolution). The images were analysed using a software based on Suzuki and Tsuchihashi’s classification. The lip print images were divided into six sections which are upper left, upper middle, upper right, lower right, lower middle and lower left. The Pearson chi-square test showed that there are significant differences (p < 0.05) between sexes in each section except for the upper middle section. In males, type V (irregular pattern) was the dominant pattern for upper left, upper right, lower right and lower left sections (ranging from 71.1% to 86.7%) while type IV (reticular pattern) was dominant at upper and middle sections (ranging from 57.2% to 66.1%). Type IV (48.3%) was dominant in upper middle section for female, while for the rest of the sections, type V was the dominant lip print pattern (ranging from 40% to 82.8%). These results showed that sex differentiation between males and females in Malaysian Malay population, Klang Valley can be suggested to be used for identification in forensic investigation.

Cheiloscopy may not be as well-known as other techniques of identification, such as fingerprint or DNA analysis, but it has its own impact in the appropriate circumstances. Cheiloscopy has been recognized as an important tool for human identification. A manual approach of studying lip prints was utilised by many researchers (magnifying glasses). Nonetheless, the current study relied solely on a mobile phone camera to visually capture lip prints for sex determination. 377 samples of lip prints were analysed with Adobe Photoshop software and classified into six different types of lip print patterns, according to Suzuki and Tsuchihashi classifications. Lip prints were divided into six sections including upper left, upper middle, upper right, lower left, lower middle and lower right. Pearson's Chi-square test revealed significant differences between male and female lip prints (p < 0.05) among the Malaysian Malay population of the Klang Valley, with Type V (irregular pattern) lip prints being the most prevalent. In comparison to magnifying glasses, our studies proved the ability to record and examine lip prints utilising a digital approach.

Cheiloscopy is recognized as a tool for personal identification due to its strength in criminalistics. In this study, the lip print of Malaysian Chinese population in Klang Valley was used for gender determination using lipstick-cellophane technique. 412 subjects (203 males and 209 females) were selected conveniently. Lipstick was first applied on the lips and the lip print was lifted using cellophane tape prior to pasting them onto a plain A4 paper and analysis using magnifying glass. Six topography areas of lip prints were classified using Suzuki and Tsuchihashi’s classification, including upper left, upper middle, upper right, lower right, lower middle and lower left. Chi-square test showed that all lip sections were significantly different from each other (p < 0.05). Type II was the dominant pattern in four lip sections for both genders: upper left (male 81.3%, female 57.4%), upper right (male 71.9%, female 42.9%), lower left (male 98.0%, female 90.0%) and lower right (male 96.1%, female 86.1%). Type IV was the dominant pattern for both middle part of the lips; upper middle (male 56.2%, female 50.7%) and lower middle (male 62.6%, female 50.2%). The results showed that gender can be differentiated based on lip print patterns. This finding suggested that cheiloscopy could be used in aiding personal identification for forensic investigation.

Fingerprints are unique structures made up of a combination of friction ridges. Due to the individual characteristics of fingerprints, it is used commonly used for identification. Traditionally, patent fingerprints are obtained using an ink pad. Unfortunately, the print takes time to dry on paper and sometimes the fingerprint will leave streaks on a finger and nearby surfaces. Alcohol gel and thermal paper could address this problem as the alcohol component in gel is a weak acid that can reacts with the leuco dyes present on thermal paper. Hence forth, this study intends to find an alternative method of obtaining patent fingerprints using various combinations of alcohol gels and thermal papers. Six donors were requested to deposit their fingerprints on different types of thermal paper using different brands of alcohol gel hand sanitisers. Quality scores based on CAST’s grading scheme were used to determine the fingerprint quality using various combinations of thermal paper and hand sanitisers. The result showed that patent fingerprints developed using hand sanitiser and thermal paper were of lower quality than the standard (ink pad). Combination of alcohol-based hand sanitiser, which consists of 70% alcohol concentration and ATM receipt paper was found to be able to produce the best quality fingerprint among the studied combinations. Despite this result, it still indicates that fingerprints using an ink pad is still the best method to record a fingerprint.

A post-mortem decomposition is defined by the evaluation of the physical and chemical changes of a cadaver or a carcass in order to estimate the cause of death and the time of death. The purpose of this study is not to replicate a real crime scene but to enhance knowledge of the effects of clothing in a decomposition process, mainly, the effects of layered cotton clothing on the post-mortem decomposition of adult female rat carcasses. Fifteen rats were divided into three groups: control, one-layered and two-layered clothed. The control subjects were unclothed and used to compare the post-mortem changes with the clothed subjects, one-layered and two-layered rat carcasses. All subjects were placed outdoor, 2.5 meters away from each other on grass bushes and dead leaves. Ambient temperature and humidity were recorded to observe if it associates with the post-mortem changes of the rats. Insect activity on each subject was observed. Post-mortem changes were measured using the Total Body Score system. The results showed that the control group underwent a faster decomposition compared to the clothed groups. The different layers of clothing did not show a vast difference in post-mortem changes. The ambient temperature of 28°C influences the post-mortem decomposition. The decomposition was rapid under the dominance of maggots compared to ants as ant colonies delayed the decomposition process. The study gave the knowledge of the effect of clothing in decomposition of female rats in forensic science.

The incidence of close-range firearm shootings on fishing vessels in Malaysia has been increasing every year. The challenge faced by law enforcement agencies is to demonstrate how these shooting crimes are carried out. To address this problem, a model of shooting angles and ricochets within a confined space needs to be constructed. This study examines the effects of shooting with the CZ 75 SP-01 Shadow semi-automatic pistol, manufactured by the Czech Republic, using 9mm FMJ bullets weighing 7.45 grams on three types of wood commonly used in fishing vessel construction: Resak, Seraya, and Balau. The factors of shooting distance (1, 3, 5, and 10 meters), shooting angles (15°, 30°, 45°, 60°, 75°, and 90°), ricochet angles, and the type of wood material (Resak, Seraya, and Balau) are investigated. The results indicate that only 114 out of 432 shots resulted in ricochets. Shots on Resak wood produced several bullet ricochets at shooting angles of 15° and 30° and a distance of 1 meter. An equation model relating ricochet angles and successful shots was developed. For Seraya wood, only a few ricochets were observed at a shooting angle of 15° and a distance of 1 meter, and statistical tests showed that an equation model could not be constructed. For Balau wood, an equation model relating ricochet angles and shooting distance was successfully established. Validation tests on the Resak and Balau wood models showed that the Resak model achieved an accuracy of 90%. However, the Balau wood model did not yield any reliable results and thus cannot be trusted. In conclusion, the three factors examined are insufficient to explain bullet ricochet occurrences when shooting is performed at close range in an enclosed space.