Monday, September 8, 2014
Reading Rocks: The 'True' Identity of Jack the Ripper, NUMB3RS, and DNA Profiling
I sat down to my computer Sunday morning to write today's blog post and -lo and behold, in my Facebook news feed, someone has discovered the identity of Jack the Ripper!
Russell Edwards, amateur Ripper sleuth and author of the upcoming Naming Jack the Ripper (release date Sept. 9), claims to have proved the identity of the most infamous serial killer in recent history, with actual forensic evidence pulled from one of the crime scenes, no less.
Take this with a grain of salt, of course, considering nearly every article I've read about this has bracketed the word proved with the ever-skeptical quotation marks and doubtless the wide-eyed sarcasm that always accompanies a pair of air quotes.
Edwards bought a blood-stained shawl at auction that supposedly came from one of the Ripper crime scenes -the murder of Catherine Eddowes- which was apparently never washed or cross-contaminated in 126 years. DNA pulled from the shawl has been 'matched' to descendants of the victim, Eddowes, as well as the man Edwards purports is the true Ripper, a mentally disturbed hairdresser named Aaron Kosminski, one of the original suspects in 1888.
Dr. Jari Louhelainen, who tested the forensic evidence for Edwards, has not yet revealed the methodology of the DNA testing he used, and I have yet to find any specifications on it. With the book's release date only two days away, I can see why they're being tight-lipped about that. "You want to know? Buy the book!"
I've decided to add my two cents to the online frenzy. I'm not a Ripper expert or an amateur sleuth or scientist, so why? As a testament to the power of reading, my friends.
People always say you can learn tons from books. Not that I've ever disputed this, but I've never been a great reader of non-fiction. Talk about the Big Yawn boring. This year, though, I have made an effort to read more non-fiction and, as I skimmed through stories about this Ripper discovery, I realized that I actually had two cents to add because of the NF book I'm reading right now. The Numbers Behind NUMB3RS: Solving Crime with Mathematics by Keith Devlin and Gary Lorden is written for the most part in everyman terms, so even I can grasp most of it (and math and science have never been my strong points). Just last night I was reading up on the chapter about DNA profiling.
Talk about timing right?
I've always assumed the margin for error in DNA profiling is astronomical, otherwise it wouldn't be such an effective forensic tool. To a point, this is true. It all depends on how many markers you're testing, and the more the better. Tackled in pages 89-104, I learned that testing nine identifying markers of a DNA sample against a database of 65,000 yielded 144 separate matches.*
As I said before, mum's the word as to the methods Louhelainen and Edwards used to match DNA, like just how many markers they used. The fact that Kosminski was already a suspect increases the probability of the DNA match in general, but if they only tested six or seven markers, the odds would greatly decrease for a true match because so many other samples could have those same six or seven markers.
In reading through these articles about the 'identified' Ripper, a lesson my dad always taught came back to me: "Never believe statistics."
Why? Because a statistician knows how to twist the statistics to show what he wants you to see.
I once saw the statistics that proved sharks are not as dangerous as people think, because more people are killed by vending machines than by sharks. See? Here is statistical proof. Sharks are just misunderstood majestic creatures with lots of sharp teeth. It's all well and good until you realize that people have way more exposure to vending machines than they do to sharks, something the statistician fails to point out.
The same idea applies here.
On the whole, I think Edwards and his publisher have accomplished a great marketing ploy. The number of markers tested, the possibility of sample cross-contamination in the lab, the likelihood that the shawl was never washed or contaminated in 126 years -all of these questions have flooded the Internet to dispute or argue the claim. Everyone has a theory. Nobody, as far I've seen, actually believes that this forensic 'evidence' is going to hold up. And you know most of them are going to grab a copy of this book to see whether the methods of Edwards and Louhelainen are infallible or not. I know I want to.
I don't know, this was just a single instance where something I read has made me think, has sent up a cautionary light in the back of my mind.
Reading is fun. Reading is informative. I've felt very intelligent while reading The Numbers Behind NUMB3RS just because I could understand a good deal of it, but the fact that I've been able to implement some of this new knowledge into actual practice just proves the intelligence gained isn't completely imagined.
So, yeah. Reading rocks, guys.
*Don't lose complete faith in this form of forensic evidence. At ten markers, 'a few' matches were found; at eleven and twelve, only one person was a DNA match, and that turned out to be a sibling. Done right, this is still an effective tool in the crime-solvers arsenal.