A Clarification of DNA Evidence Given at Scott Watson's Trial

A Clarification of DNA Evidence

Given at Scott Watson's Trial

A Clarification of DNA Evidence Given at Scott Watson's Trial


A chronology of events:


Police apply for warrant to seize Scott Watson's boat.


Hair samples taken by police from Hope residence.


Scott Watson's boat seized by police.


A letter from Scott's sister found beneath the mattress of the forward bunk.


One blonde hair found on pillow of forward bunk (directly beneath the open hatch). Blanket sent to ESR in Auckland.


Blanket examined in Auckland. hairs removed and stored in two bags and labeled YA69.


Bags of hair examined by ESR scientist for blonde hair suitable for DNA testing. 

Late February 98

Further hair requested by ESR and collected from hope residence. This too is labeled, it seems, STO5. No count is made of reference sample hairs.


STO5 hairs examined at ESR lab. YA69 hair also examined. These examinations occur at the same worktable and are performed by the same scientist. Two  blonde hairs are then said to be found in YA69 sample. The lengths of these are 150mm and 250mm respectively. They are labeled YA69/12-13.


YA69 hairs are finally counted and classified by ESR scientist. Three more blonde hairs are located. These are attributed to Scott's neices. When these are taken into account it becomes extremely odd that these blond hairs could be missed in the initial screenings when only five of 389 were blonde and all the rest of a dark colour.



Without stating one of the obvious conclusions that could be drawn from the proximity of the first two events above, there was a strong possibility of the transfer of these two hairs on the 7th of March 1998 when both STO5 and YA69 hairs were examined on the same table, on the same day, by the same scientist. That there was an unexplained cut in the plastic bag containing the STO5 hairs is also of interest. The ESR's accreditation required them to not have evidentiary hair and samples in the lab at the same time - but that they ignored that as likely to make getting results slower. There was, at the time of the trial, a ministerial inquiry underway, into practices at the ESR laboratory. One of the recommendations of this report, when it finally appeared, was that, Scene samples and reference samples should not be tested in the same building, let alone at the same work table. This blanket and the hairs on it had been examined on three previous occasions by ESR scientists (14th Jan. In situ, 19th Jan. At ESR lab and 22nd Jan. At ESR lab) and it was not until the March 7th examination that the crucial two hairs were found. It is also interesting to note that both the ESR and Police have recently been allocated funds to remedy the above faults in their scientific proceedures.

We are now seeing the 'wheels falling off' in a number of government departments through the cost cutting of the past fifteen years. This it would seem was the case when due to Scott and Ben Smart having a similar hair colouring, it was decided by the ESR scientist, not to test for Smarts DNA as it would take too long (and thus be too expensive). Could the fact that Smart did not live at home, and no samples were available of his hair, other than pubic hair from a pair of long johns, have anything to do with none of his hair being found on the boat?

The results of the ESR's testing left much to be desired as well. The original test, which was not able to be replicated, returned a statistical probability, (or odds if you will) for this test alone being only 448 times more likely, or one in every 448 people has this same hair. This result was only obtained from one of the hairs, YA69/ 13. The other gave no result in New Zealand.

The DNA obtained by the ESR, (not the sample hair) was then sent to an Australian laboratory for further testing. No reagent blank, which is a sample of a known result that is run alongside any test to show up any errors, was supplied to the Australian lab. Their test on this DNA multiplied with the N.Z. test brought the statistical probability to 28000 times more likely. This is not a large number when other DNA tests that we hear of have odds that are well into the millions and still not 100% conclusive. 

The NZ test at 448 times more likely meant there would be on average 3-4 people at Furneaux Lodge that night with that same DNA profile. The Australian result of 700 times more likely meant on average there would have been 2-3 people with the same DNA. In the real world this would be an inconclusive result, however in the world of operation TAM the show must go on and these two numbers were multiplied to give a more favourable result.

What was left of the hairs was then sent to England for mitochondrial DNA testing. This is a completely different test and only confirms DNA in the female genetic line the results that were obtained there were doubtful to say the least. Only one hair produced a result and the other gave a mixed profile showing the presence of two or more person DNA. Possibly sweat from the hands of the police officer that collected hair from the Hope residence using his bare hands and a used plastic envelope to contain the sample. The hair that gave a result matched in only twelve of the thirteen positions on the DNA chain and also showed signs of contamination.

The results that were returned from these tests were far from conclusive, leaving out the possibility of the mixing of samples. When this possibility is taken into account along with the unexplained cut in the bag containing the sample STO5 and the recommendations of the ministerial inquiry, there is grave doubt about the resulting conclusions.

We have been conditioned to think of the forensic sciences as being infallible, finger prints and DNA are revered as akin to magic but on close examination leave a lot to be desired.


Cleaning Evidence


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