Anomaly detection for internet surveillance

Many threats in the real world can be related to activity of persons on the internet. Internet surveillance aims to predict and prevent attacks and to assist in finding suspects based on information from the web. However, the amount of data on the internet rapidly increases and it is time consuming to monitor many websites. In this paper, we...

Re-identification of persons in multi-camera surveillance under varying viewpoints and illumination

The capability to track individuals in CCTV cameras is important for surveillance and forensics alike. However, it is laborious to do over multiple cameras. Therefore, an automated system is desirable. In literature several methods have been proposed, but their robustness against varying viewpoints and illumination is limited. Hence performance...

Modelling a crime scene in 3D and adding thermal information

Once a crime has been perpetrated, forensic traces will only be persevered in the crime scene for a limited time frame. It is therefore necessary to record a crime scene meticulously. Usually, photographs and/or videos are taken at the scene to document it, so that later on one will know the exact place of an object. Another possibility is to...

Shoe print examinations: Effects of expectation, complexity and experience

As trace evidence is becoming more and more important in legal cases it has to be ascertained that accurate judgments are made. In the present study we investigated how expectations and complexity affect shoe print examinations and to what extent differences exist between beginners and experienced examiners. Twelve examiners assessed similarity...

Postmortem time estimation using body temperature and a finite-element computer model

In the Netherlands most murder victims are found 2-24 h after the crime. During this period, body temperature decrease is the most reliable method to estimate the postmortem time (PMT). Recently, two murder cases were analysed in which currently available methods did not provide a sufficiently reliable estimate of the PMT. In both cases a study...

Earwitnesses: Effects of speech duration, latency and acoustic environment

An experiment was conducted to investigate the reliability of voice lineups. More specifically, the experiment was designed to look into the effects of retention interval (an immediate test or after a week), speech duration (30 or 70 s) and acoustic environment (indoors or indoors and outdoors) on speaker identification accuracy. In addition,...

Searching for evidence: Knowledge and search strategies used by forensic scientists

The Forensic Science Laboratory of The Netherlands is suffering from a growing backlog due to an increasing number of cases, which results in long delivery times of research reports within a number of departments. The project, "Strategies for Searching Trace Evidence," was started by the Forensic Science Laboratory in order to increase the...