Wednesday, December 31, 2008
(Hat tip to Forensic Focus)
Wednesday, December 24, 2008
One of the podcasts I enjoy on a frequent basis is All in the Mind, by ABC Radio National (Australia). Last week's episode was titled "Untangling Tricky Talk" and covered forensic linguistics as well as transcription by deaf people. The forensic linguistic portion was centered around an interview of Paul Foulkes, who gave a very professional account of his discipline.
Tuesday, December 23, 2008
Of course, susceptibility to tampering is not the only thing to be considered when evaluating the relative merits of digital imagery as evidence, but it is obvious that tampering with a digital copy is easier to do and (possibly) get away with than tampering with film or tape.
Farid first conceived of the possibilities of digital forensics while at MIT, waiting in the checkout line at the library. Restless, he picked up a copy of the Federal Rules of Evidence, then started randomly reading. What he saw startled him: Film and digital images were equivalent evidence, in the eyes of the court.
"This just seemed like a bad idea,'' he said. "Not that I'm good at seeing the future — but I could tell this would be a problem."
Sunday, December 14, 2008
If any of you readers did see the episode and would like to fill us in, please do!
Tuesday, December 02, 2008
These devices work by emitting an RF (radio frequency) radar pulse, listening for the reflection of that pulse off of objects in the wall and on the other side, and using time-delay (i.e. how long it takes for the reflected pulse to come back) and direction (i.e. which direction did the reflection come from) information to construct a picture. This is similar to how bats and dolphins use acoustic echo location, just with an RF pulse instead of sound pulses.
This is a handy capability to have in hostage and other situations where a team has to enter a building where armed attackers or booby traps might be waiting for them. The engineering problems that had to be solved in order to come up with a deployable system were extremely challenging - my had is off to the teams that did this.
PS. In case you are interested, I posted some time ago about a DARPA (Defense Advanced Research Projects Agency, US Department of Defense) effort that developed a through-wall motion detector which was compact and lightweight - so light-weight that you use it with a single hand, like a stud-finder. That post can be found here.