Sunday, July 19, 2015

Bulletin: DNA match statistics overstated, news delayed scheduled execution: "The math error overstated at trial: "Williams is black, and prosecutors said the probability of another black person with the same DNA profile found in [the victim's] missing car was one in 40 sextillion. Jurors in 2006 were told the probability was one in 43 sextillion. A sextillion is defined as a 1 followed by 21 zeros." Of course, there are only 7 billion (nine zeroes) or so people on earth, so that statistic essentially told jurors it's nigh-on impossible it was anyone else."

"The Texas Department of Public Safety sent a notice June 30 that the FBI-developed population database used by the crime lab in Texas and other states had errors for calculating DNA match statistics in criminal investigations." The Texas Attorney General's Office informed attorneys for Clifton Lamar Williams of the issue on Wednesday and the Court of Criminal Appeals halted his execution scheduled for Thursday night and ordered the trial court to hold a hearing.The math error overstated at trial: "Williams is black, and prosecutors said the probability of another black person with the same DNA profile found in [the victim's] missing car was one in 40 sextillion. Jurors in 2006 were told the probability was one in 43 sextillion. A sextillion is defined as a 1 followed by 21 zeros."  Of course, there are only 7 billion (nine zeroes) or so people on earth, so that statistic essentially told jurors it's nigh-on impossible it was anyone else.........Perhaps the racial frame cast upon the testimony explains the astronomical numbers. In previous coverage of the issue I've never seen overestimates range to the sextillions, which sounds like the forensic analyst and the DA in my hometown employed a particularly extreme version of this error at Mr. Williams' trial. Regardless, the DPS notification affects lots of cases besides his, even if delaying Williams' scheduled execution appears to have engendered the first public report of the DPS notice, that I've seen anyway. The Hays County DA posted a copy of the notice from DPS on their website."(Thanks to Grits for Breakfast for bringing this story to our attention);
http://gritsforbreakfast.blogspot.ca/2015/07/dna-match-statistics-overstated-news.html