Forensic Examination of Portable Eletronic Devices (PED)

Abstract

Portable electronic devices (PED) are used worldwide in the community. Many of these devices have display screens made up of glass which is vulnerable to breakage. PED function with a damaged screen which results in individuals not replacing them as often as other glass objects such as vase or windows. Broken PED can be a source of glass and significant on the clothing and belongings of individuals suspected in offences involving breaking of glass and even the public. The forensic implications of PED glass were investigated. There were three objectives investigated. The first one involved identifying whether glass fragments can get transferred from mobile phone display screens (a portable electronic device (PED)) to the pockets of clothing (jacket and jeans) which the phone screen has any form of damage on it. There were fragments found in both the clothing whether the phone was the least damaged or the most damaged over all the periods of time tested- 1 hr, 2 hr, 4 hr and 8hr with a minimum of 4 to 5 fragments of glass found over any duration of time within the time frame. More number of glass fragments are found when the individual is active and fewer glass fragments are found if the individual is less active. The second objective is to identify if PED has a refractive index (RI) different from sodalime glass and if it can be used to distinguished between different phone brands. The results found suggest that the refractive index measurement can be used to indicate a possible brand. However, since the sample size is small more research will need to be conducted to help strengthen the results. The results show that PED glass is different from soda-lime glass and can therefore be distinguished from bottles, window glass etc which is a common occurrence in forensic cases. The third objective is to find the elemental composition of the mobile phone screens to with identify whether the source of glass present is mobile phone screen or another type of glass. The variation in potassium assisted with the identification of the PED glass provided that the glass recovered for case work is from the surface of the display. The results found during this research do not account for all the mobile brands and models. More research will need to be conducted to determine the refractive index and the elemental composition of other models. The refractive index values and elemental compositions of PED glass were significantly different to soda-lime glass (e.g., windows and bottles) usually encountered in casework and therefore RI and elemental composition can be used to distinguish these sources of glass.