MELENDEZ-DIAZ v. MASSACHUSETTS

The recent Supreme Court of the United States (SCOTUS) deci­sion in Melendez-Diaz v. Massachusetts has sent a shock­wave through the foren­sic sci­ence com­mu­nity in the United States.

In a com­mu­nity com­ment forum for foren­sic sci­en­tists, there was a com­ment from an ana­lyst from another coun­try, that stated they didn’t see what the big deal was with the rul­ing, because in their coun­try, they are rarely called, because the judges usu­ally already know about the sci­ence, and make their rul­ings on guilt or inno­cence using just the writ­ten report. I replied with the following:

The dif­fer­ence is that in the USA, it isn’t a judge deter­min­ing the out­come of the case. Instead it is a jury of cit­i­zens who might never again sit on the same type of case to become “experts” themselves.

Concerns are a bit overblown though. First of all it is the duty of a foren­sic sci­en­tist to not only analyse evi­dence accu­rately, but to also be able to pro­fes­sion­ally, accu­rately, and impar­tially explain what tests they per­formed, what the results were, and what that means in rela­tion to the case.

Some juris­dic­tions have “shel­tered” the sci­en­tists from hav­ing to stand up to cross exam­i­na­tion regard­ing their work. The court rul­ing will cause those who can’t tes­tify well to either quit, get fired, or be pro­moted to posi­tions where they won’t have tes­tify [off the bench super­vi­sory positions].

As time goes by, the local defense com­mu­nity will no longer want the sci­en­tist to actu­ally tes­tify, and will stip­u­late to their results — as long as that par­tic­u­lar sci­en­tist does a good job tes­ti­fy­ing. Then it will be the pros­e­cu­tors insist­ing the sci­en­tist tes­tify in order to put on a “dog and pony show” for the jury.

High vol­ume dis­ci­plines will be the most effected. When I did drug analy­sis (200 cases a month) and blood alco­hol analy­sis (1500 sam­ples a year) I would tes­tify roughly once a month in drug cases and two to three times in DUI trials.

The vol­ume of tes­ti­mony isn’t that bad.

Unless of course you either don’t tes­tify well and the defense feels they can make you look like an idiot on the stand, or if you are respon­si­bly for breath alco­hol devices — then you will likely tes­tify more often.

Now here in Arizona this rul­ing has lit­tle to no effect. In other areas this could have pro­found impact as sci­en­tists will start to have to sup­port and defend their work against cross-examination, and they will have to answer before a jury if they are caught per­form­ing shoddy work, or using unac­cepted techniques.

After the recent NAS Report, this SCOTUS rul­ing will help strengthen the reli­a­bil­ity and accu­racy of foren­sic work as pointed out by another sci­en­tist on the same com­mu­nity board, because ana­lysts will have in mind to do their best work, as they will poten­tially have to tes­tify in court now.