Volume 14. Number 1
December 2015

Original Articles

Video Frame Classification Based upon Motion Vectors 

Ting-Yu Hsu ; Wen-Kuei Lin ; Che-Yen Wen

Abstract:Closed-Circuit Television (CCTV) surveillance systems play an important role in crime scene investigation. Investigators use recorded video data to find suspects and information to solve crime cases. However, there are usually a lot of unwanted or tedious frames (e.g., background without meaning) in surveillance videos. It is an exhausting and time-consuming work for investigators to search entire videos for interested information. The most difficult problem of video data is how to find useful and meaningful frames from them. In this paper, we provide a method of utilizing motion vectors to classify video frames based upon moving information (such as orientation). By the proposed method, investigators can reduce the time of searching objects from surveillance videos, and focus on frames with moving objects.

Identification of Full and Partial Prints Using an Automatic Identification System

Marta Szpilowska ; Lama Appesh ; Jennifer J. Jackiw ; Marcel Roberts ; Gloria Proni

Abstract: In this paper, AFIX Tracker, a minutia-based fingerprint identification system developed by AFIX Technologies, was used to search 1000 rolled prints against a database of pressed fingerprints. In the analysis, the minutiae were extracted manually or with the help of the Smart Extract feature, included in the software package. It was found that a manual extraction of minutiae is highly more preferable to the automatic feature in order to have high values of fingerprint identification. Moreover, the quality of the prints and their sizes was found to be the limiting step. Because a full fingerprint of reliable quality is not always found at a crime scene, the analysis of partial prints of different dimensions was also investigated. It was found that area of fingerprints up to 1 cm^2 could be easily identified.

A Survey of Level II Friction Ridge Detail in Palm Prints

Hunter Johnson ; Laura Deimel ; Well Howell ; Marcel Roberts ; Gloria Proni

Abstract: This paper considers the problem of uniquely identifying an individual based on a palm print. We survey 100 palm prints, tallying the number and locations of 12 friction ridge characteristics (minutiae) on each palm with the assistance of an automated print identification system (AFIS) called AFIX Tracker. After binning the data set by frequency ranges, the individual entropy values are calculated for every minutia in each section of the palm. The minimum entropies for each minutia/section combination are summed to provide a probability of misidentification based on a full palm print. Our results show that the probability of misidentification is on the order of 10^(-29). This mirrors previous reports in the literature that estimated 10^(-20) for fingerprints and even improves upon it.

The Quantitative Determination of Opiates and Amphetamines in Oral Fluid by Direct Injection Liquid Chromatography-Tandem Mass Spectrometry

Hsiu-Chuan Liu ; Yu-Shan Wang ; Ray H. Liu ; Dong-Liang Lin

Abstract:A sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of opiates and amphetamines in oral fluid was developed and validated. A simple sample preparation of oral fluid involving centrifugation and injection of 10 μL of the supernatant substantially reduced total analysis time. Owing to the basic nature of the drugs and their metabolites, LCMS/ MS analysis was performed by reverse-phase chromatography and electrospray ionization (ESI) which is a rugged and efficient ionization technique for basic drugs. Stable isotope-labeled internal standards were used in the analysis and the calibration to compensate for any matrix effects. The method was fully validated with the linearity of the developed method established in the concentration range of 1 to 500 ng/mL and the limits of detection and quantitation were 1 ng/mL for amphetamine, methamphetamine, morphine, codeine, 6-acetylmorphine and 6-acetylcodeine. The precision and accuracy were determined by spiking oral fluid samples at six concentration levels. For all analytes, the relative standard deviations of intra- and inter-day precision were 0.9 to 6.4% and 0.9 to 12.9%, respectively. The method was also successfully applied to the analyses of 34 oral fluid specimens collected from patients participating in the substitution therapy program.

Evidence Revelations at Memory Forensics in Conversations of Instant Messages

Cheng-Ta Huang ; Ya-Ting Chang ; Shiuh-Jeng Wang

Abstract: Instant messaging software is typically installed in a Microsoft Windows-based computer. Forensic procedures provide evidence for legal purposes after such software is used. Web-based instant messaging leaves no chat messages on the hard disk but some may be dumped into memory, the paging file and unallocated hard disk space. The targets in this paper are the software ”Skype” and the web version of ”Facebook Messenger” in Windows operating system. Proposed memory forensic technology is used to collect key evidence of communication records and the stepwise process demonstrated. The user’s login username, password, contact list, and conversation records are obtained for the purposes of reconstructing a crime.

Artificial Aging Tests on the Samples of Staedtler 430M Red Ink, Corvina 81 Red Ink and Rhodamine 6G Red Dye by Means of Fluorescence

Hu-Sheng Chen

Abstract:It is assumed that ink does not age in the cartridge, but only after it is placed on paper where dyes fade, solvent diffuses and evaporates and resin polymerizes. This study employed fluorescence detection after an optimal HPLC separation of the artificially aged samples of two inks and one dye. It was proved that the aging process was related with photo-degradation of dyes present in the inks, but not heating. The measured ratio changes of peak heights of the existing peaks over the extra peaks arising from the artificially aged dye contained in the inks clearly showed a function of exposure time to normal daylight and could be used to establish an aging curve.