Just how accu­rate are blood alco­hol results? This is the sub­ject of much dis­cus­sion in the realm of DUI cases. There are numer­ous ways to approach an error rate (or uncer­tainty rate), but it cer­tainly needs to be approached.

When foren­sic sci­en­tists tes­tify that the defen­dants blood alco­hol con­cen­tra­tion is X, intel­lec­tu­ally they KNOW what­ever result they obtained, it is likely NOT the actual BAC the sub­ject had at the time of the blood draw. There is always an error rate, asso­ci­ated with any sci­en­tific mea­sure­ment. It’s fair to debate what that error rate might be, but an ana­lyst who either refuses to acknowl­edge an error rate, or ascribes to a “zero” error rate, is being intel­lec­tu­ally dishonest.

A local attor­ney is chal­leng­ing the state police crime lab on how sci­en­tists mea­sure blood alco­hol tests. He says the tests are not reli­able. It’s a mes­sage police make clear all the time– over the limit, under arrest, but now one local attor­ney is fight­ing how the limit is measured.

The issue all stems from a felony drunk dri­ving case out of Ludington. Attorney Mike Nichols says the Michigan State Police Crime Lab does not give a mar­gin of error when per­form­ing blood alco­hol tests.

Michael Nichols, Criminal Defense Attorney: “What they’re say­ing is our results are essen­tially per­fect, and we know noth­ing is perfect.”

Nichols says tox­i­col­o­gists run two dif­fer­ent blood sam­ples through two dif­fer­ent blood alco­hol machines. If the results are within a cer­tain range, they’re con­sid­ered reli­able, but Nichols argues tox­i­col­o­gists drop off the third num­ber in blood alco­hol tests, so he says the end result isn’t accurate.

Michael Nichols: “The prob­lem is, mea­sure it and tell us how reli­able is very reliable.”

Read the whole arti­cle on WLNS.com.