Wednesday, April 7, 2010

Actual Innocence Scorecard: What Good Is It?

Previously, I introduced the concept of an Actual Innocence Scorecard and discussed the meaning of an Actual Innocence Score. In this post, I'll give an example of the value of such scoring.

Northwestern University has a web page listing 39 individuals executed though possibly innocent. You can't help but run across that page multiple times if you are researching the subject of wrongful executions. I'll give you the money quote from that page, and I'll include that portion of the list consisting only of those Texas may have wrongfully executed.

Off Topic: 7 Apr 2010

James Lileks is an interesting guy. He writes, frequently of mid-century culture. We have three of his books: The Gallery of Regrettable Food, Mommy Knows Worst, and Interior Desecrations. I still can't look through any of them without suffering some bizarre mixture of horror and laughter.

Take a browse through his tour of a Knudsen recipe book. Start here, then use the "Next" button to page through the book. The food images are  too ghoulish to show here, even as thumbnail. Lileks' narrative is sublime.

Bon appetit!

On Coins, Dice, and Lethal Injections

“They told me there would be no math.” -- Chevy Chase as President Gerald Ford on Saturday Night Live, 1975.

What are the chances that if you could flip a coin 10 times it will not once turn up "tails?" In other words, what's the chance of 10 "heads" in a row? The odds can be calculated as:

1/2 x 1/2 x 1/2 x 1/2 x 1/2 x 1/2 x 1/2 x 1/2 x 1/2 x 1/2 = (1/2)^10 = 0.001 = 0.1%

What are the chances you could roll a die ten times in a row and not have it once turn up "1?" In other words, what's the chance of getting somewhere between 2 and 6, ten times in a row? That answer can be calculated as:

5/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 = (5/6)^10 = .162 = 16%

Now here we go.  Texas has exonerated 2.4 people from death row for every 100 they have executed. (The other 49 states have exonerated 14 people from death row for every 100 they have executed.) Assuming that for each lethal injection in Texas there is a mere chance of 2 in 100 that the convict is innocent, what's the chance that Texas has not executed an innocent person among its 451 lethal injections?

(98/100)^451 = 0.011 = 0.01%

That's one chance in 10,000. And that assumes that the Texas death machine is 98% accurate.

Not bloody likely.

tsj
7 Apr 2010