Fallacious?

Published: 10 hrs ago

Jeopardy law rapist gets life

"Coward ... rapist WB

A MAN who raped an OAP 16 years ago was jailed for life yesterday — after the double jeopardy law was overturned.

WB, 56, beat and raped a mum of one, 66, in her home in Stratford, East London, in 1997.

He was cleared in 1999 after a judge ruled DNA evidence against him could not be used against him.

Back then, a person could not be tried a second time for the same crime and builder B thought he had got away with it.

But changes to the law in 2005, to allow those cleared of a serious offence to be put on trial for the crime again, meant B could be retried for the rape.

Jurors at London’s Old Bailey were told a one-in-a-billion DNA match linked the grandfather of six, of Walthamstow, to the attack.

Coward B refused to come up from the cells to be sentenced.

Ordering he serve a minimum 10½years, Judge Peter Rook said he had committed a crime of “extreme violence and depravity”.

B beat his victim so badly she was unrecognisable. She died in 2002. Her family said: “She never got over it.”"

http://www.thesun.co.uk/sol/homepage/news/4989218/Jeopardy-law-rapist-gets-life-in-prison-after-being-originally-cleared-in-1999.html

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Prosecutor's fallacy

"The prosecutor's fallacy is a fallacy of statistical reasoning, typically used by the prosecution to argue for the guilt of a defendant during a criminal trial. Although it is named after prosecutors it is not specific to them, and some variants of the fallacy can be utilized by defence lawyers arguing for the innocence of their client.

At its heart the fallacy involves assuming that the prior probability of a random match is equal to the probability that the defendant is innocent.

For instance, if a perpetrator is known to have the same blood type as a defendant and 10% of the population share that blood type; then to argue on that basis alone that the probability of the defendant being guilty is 90% makes the prosecutors's fallacy, in a very simple form.

The terms "prosecutor's fallacy" and "defense attorney's fallacy" were originated by William C. Thompson and Edward Schumann in the 1987 article Interpretation of Statistical Evidence in Criminal Trials, subtitled The Prosecutor's Fallacy and the Defense Attorney's Fallacy.

The fallacy can arise from multiple testing, such as when evidence is compared against a large database. The size of the database elevates the likelihood of finding a match by pure chance alone; i.e., DNA evidence is soundest when a match is found after a single directed comparison because the existence of matches against a large database where the test sample is of poor quality may be less unlikely by mere chance.

The basic fallacy results from misunderstanding conditional probability and neglecting the prior odds of a defendant being guilty before that evidence was introduced.

When a prosecutor has collected some evidence (for instance a DNA match) and has an expert testify that the probability of finding this evidence if the accused were innocent is tiny, the fallacy occurs if it is concluded that the probability of the accused being innocent must be comparably tiny.

If the DNA match is used to confirm guilt which is otherwise suspected then it is indeed strong evidence. However if the DNA evidence is the sole evidence against the accused and the accused was picked out of a large database of DNA profiles, the odds of the match being made at random may be reduced, and less damaging to the defendant.

The odds in this scenario do not relate to the odds of being guilty, they relate to the odds of being picked at random."

http://en.wikipedia.org/wiki/Prosecutor's_fallacy

The Prosecutor’s Fallacy

http://buchanan.blogs.nytimes.com/2007/05/16/the-prosecutors-fallacy/?_r=0