Archive for the ‘law enforcement’ Category

Virtual Police Line Up

May 14, 2008

Check out this interesting video of a virtual reality police line up. the system was developed at Stanford’s Virtual Human Interaction Lab and depicts several interesting concepts employing virtual reality to improve the line up process. The VHIL’s research was performed in collaboration with the Research Center for Virtual Environments and Behavior, the National Science Foundation, and the Federal Judicial Center. the goal of the work is to apply virtual environments to deepend understanding of how witnesses of crimes identify suspects.

The eyewitness observes the suspects through viewing a virtual environment delivered to a head mounted display, although I can see no reason why a similar set of functionality could not be delivered to a screen based system. This allows the eyewitness to potentially be at a remote or distant location from the suspects, who need not even all be present at one location themselves.

The use of a 3D interactive environment also makes it is possible for an eyewitness to not only to see the individuals in the line up from the front, but also to “fly around” them and view them from different angles or even from just inches away.

This also makes it possible to place the line up in a different virtual location, perhaps into a scene similar to where the crime was committed.

Unfortunately, the virtual line up as implemented suffers from several weaknesses. First, the current implementation uses digital “busts” glued onto representative bodies. While this approach allows for the creation of digital “foils”, simulated persons similar in appearance to a true suspect, it also means that facial motion can not be presented. This representation can be misleading also because the body shape, stature, and clothing may not be accurate representations of the suspects’ true appearance. It also limits the ability to employ realistic representations of distinguishing marks not found on the face, i.e. tattoos and scars.

Second, as implemented, the virtual busts have no ability to be animated in real-time. Facial motion is known to be an important cue in facial recognition and this work ignores some of the well known results in the study of human face and person recognition abilities here. Finally, the avatar body motions are completely fake eliminating the use of any cues related to body motion, gait, etc. which have also been shown to aid recognition.

Unfortunately these limitations of the head mounted virtual reality based line up are likely to prevent its use in any real world line ups. A better approach would seem to be using blue/green screen video based capture of real suspect images possibly from multiple cameras, and image based rendering to generate the virtual face views. See for example this research and the research at the Fraunhofer Institute into image based rendering of faces for virtual conferencing.


Will commercial security software detect police key loggers?

July 17, 2007

Following on the heals of his recent story that a judge approved the use of keylogging software in a DEA case in order to thwart a criminal using encryption, Declan McCullagh and CNET have released the results of his recent survey of PC security software companies which claim they will detect police spyware.  All the companies surveyed claim they can detect police spyware; however only a few acknowledged that they might, at least under threat of a court order, fail to report these detections to the user.  This is an interesting follow up to the 2001 report that MacAfee took measures to avoid detecting FBI spyware. 

Ed Felton reported on audio keylogging a couple of years back, and of course screens and keystrokes can also be captured in some cases by using remote monitoring or screen capture software, by capturing radio emissions, or simply with hidden video cameras.  The average person simply can’t be certain one or more of these techniques isn’t being employed against them.

And it isn’t just law enforcement that has access to these surveillance tools today.  These tools are readily available to high tech criminals and others that might want to know what you are doing on your computer.   For example, keyloggers are sometimes posted to boards and game sites.  Unfortunately, not only can’t you be sure that your security software will detect a particular piece of keylogging or screen capture software, some security software just plain doesn’t work in many cases.  Caveat emptor.  If you want to be sure, you’ll have to write your own software.

Interestingly, at the current time keylogging software is not readily available for most PDAs and mobile devices, while encryption software is.  Future criminals and crime fighters take note.