Airdate: Dec 15, 2009
Scientist: Dwayne Wisbey
Kids' Science Challenge: Forensics - Secret Message
When incriminating evidence is written on a pad of paper, forensic scientists can reveal that message long after the page is removed.
JM: Suppose your kid writes a note to Santa, rips the page off a memo pad, and sends it on to the North Pole. You might be curious about the contents of that gift list, and if only you had an ESDA, reading that message wouldn’t be a problem. I’m Jim Metzner and this is the Pulse of the Planet. Dwayne Wisbey is a forensic document examiner at the Wallie Howard Jr. Center for Forensic Sciences, in Syracuse, New York.
DW: This instrument is called the electrostatic detection apparatus. If you had a pad of paper, and you wrote a note on it and you pulled the piece of paper off, the paper below it would have indentations of the writing that you just wrote the note on. So sometimes those indentations are such that you cannot see them with the unaided eye. This instrument allows us to try to visualize those writings that were left by a prior piece of paper that was in contact with the one below it.
JM: Dwayne’s not using that ESDA for wish list recovery, but it does come in handy for analyzing writing paper found in crime scenes, deciphering threatening notes, and helping to compare known and questioned writing samples. An ESDA can detect writing indentations several pages into a pad, but that’s not the only reason for using this high-tech tool.
DW: You’ve seen on TV where someone will take a pencil and rub over a document that they believe has indentations on it. Now the problem with that is, that rubbing covers up potential evidence. If somebody had a fingerprint and that was next to where the indented writing was, that might destroy that print. So that’s why we use this instrument, rather than pencil rubbings.
JM: On our next program, we’ll hear how an ESDA actually works. Dwayne Wisbey is a participant in this year’s Kids’ Science Challenge, our free nationwide competition for 3rd to 6th graders, made possible by the National Science Foundation. Check out kidsciencechallenge.com. I’m Jim Metzner.