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Tags Australia cases , dna evidence , murder cases

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Old 22nd July 2020, 04:49 PM   #121
Chris_Halkides
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mind the gap

"Mr Yovich also referred to a contamination event that occurred in a UK lab in 2007, when an ex-employee’s DNA was detected on a DNA test negative control blank 16 months after they had resigned...Having read the incident report, Justice Hall clarified with Mr Yovich during his cross-examination of Dr Whitaker that the contamination could have occurred while the employee was still in the lab, but was not detected until later." link

The quote above is from an article on the Claremont murder case. Either way the DNA persisted. I would point to the Annie Le case as an example of DNA persisting in a less than pristine environment. Ms. Lee was a graduate student who was murdered by Raymond Clark. Another person's DNA was found on one sample from her underwear.
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Old 24th July 2020, 04:52 AM   #122
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Originally Posted by Chris_Halkides View Post
"Mr Yovich also referred to a contamination event that occurred in a UK lab in 2007, when an ex-employee’s DNA was detected on a DNA test negative control blank 16 months after they had resigned...Having read the incident report, Justice Hall clarified with Mr Yovich during his cross-examination of Dr Whitaker that the contamination could have occurred while the employee was still in the lab, but was not detected until later." link

The quote above is from an article on the Claremont murder case. Either way the DNA persisted. I would point to the Annie Le case as an example of DNA persisting in a less than pristine environment. Ms. Lee was a graduate student who was murdered by Raymond Clark. Another person's DNA was found on one sample from her underwear.
You have to separate two things, DNA of an employee and DNA of a sample.

Unlike samples, employees tend to walk around and deposit their genetic material on everything they touch. This is unavoidable, there is your DNA on your mouse, phone, on the door knob you used, toilet seat, everywhere. This is a fact of life and forensic laboratories are well aware this is a possibility (and is a major reason why DNA testing is such a great tool). What likely happened here is that the employee in question left their DNA on a piece of equipment or consumables that wasn't used until many months later. DNA can persist there, this is not a question, but the object in question was not used, that's why the contamination wasn't picked up until much later.

If I had to guess I'd say it might've been a pipette that the employee liked to use but other employees for whatever reason did not. Over a year later someone used that pipette for whatever reason and found the contamination. Other possibilities include consumables that were ordered in bulk and the employee in question stored (and hanlded them impropertly) or something of that nature. It wasn't something routinely in use that just happened to deposit their DNA 16 months later, but it could've happened at any time prior. This doesn't happen, something was done differently in that run to all the others.

Samples, by the virtue of being, well "not alive", are much more inert and do not deposit themselves all over the place. This is especially true for a known sample contaminating an unknown sample, because there are multiple safeguards aimed at preventing exactly that scenario.

The point is, an employee leaving a trace of their DNA is not an indication the same could happen to a sample. The contamination probably happened outside of clean area where samples are handled. In either event it is not an indication of a known sample contaminating another known sample as being possible, let alone likely.

Again, random chance should be mentioned. Suppose all this happens, what are the odds that a known sample contaminating something that would implicate this particular person? A laboratory processes hundreds of unknown samples each week, if this two events happened months apart you're talking about odds of well under 0.01% - and that is assuming the cross-contamination did happen (which is infitesemal). It's far more likely some random sample unconnected to the case would be contaminated than this particular sample would.

I mention this because for this to have any merit at all, one would expect it happens in the laboratory with some regularity before it becomes relevant. If there is no indication such a contamination is a problem the laboratory grapples with, then police framing is a better explanation than accidental contamination.

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Old 24th July 2020, 05:04 AM   #123
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Originally Posted by Chris_Halkides View Post
Let me begin with mixtures then move on. Once you get to a 10:1 mixture or so, it becomes more difficult to differentiate stutter peaks from real peaks. More generally, analysis of mixtures is prone to subjectivity and bias. A good example of a suspect-centered analysis in the work that Stefanoni did with respect to the bra clasp profile in the Knox/Sollecito case. She found Sollecito's profile, yet other peaks she called stutter, even though some would have had to have been backwards stutter peaks (which is quite uncommon).
As far as I'm concerned, DNA should be thrown out of Knox/Sollecito case. Yes, stutter peaks are a (known) problem.

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That Professor Thompson knows about these sorts of problems is suggested by the fact that he is a coauthor on a paper (snipped for readability)
I'm not calling their expertise into question. I'm saying this particular article is not a scientific article on this topic.

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Now I would like to address more generally the need to have lawyers oversee forensics.
I'm not quite sure "oversight" is the word I'd use. They need advice and occasionaly guidance from lawyers trained for this sort of thing, but not oversight.

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Why does forensics need oversight from lawyers such as Professor Thompson and others? First, because it blends law and science. Such a statement may seem banal, but this overlap is more complex than it first appears.
Banal? No. Completely accurate for a much wider topic than mere forensics. Proving someone did (whatever) and proving it in court beyond the realm of reasonable doubt can be and often are two very different sets of standards. This is the price we pay for a democratic society and I welcome it.

But this is not oversight. It's a good reason why you would want to rotinely consult a lawyer (and maybe a prosecutor) to inspect the laboratory, find possible faults to use in courts and correct them to their satisfaction, or explain why that is impossible.

Oversight is a far more encompassing term that would see lawyers tell forensics what to do and how. This is not possible, most forensics are better versed in law than lawyers are in forensics. Lawyers can be useful to find potential holes you can plug before they become relevant, though not as oversight.

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Let me provide just a few examples of the second reason. As Professor Thompson documented in "Tarnish on the Gold Standard," the negative controls have been shown to have been faked
Now look, "faked" is a different topic entirely. If the laboratory is routinely faking their results, that's a good enough reason to throw all their results out without even examining them. The assumption I make is the laboratory is not deliberately skewing the results in their favor and working in good faith.

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Others documented that forensic reports in the Duke lacrosse and Steven Avery cases were shown to have been incomplete and highly misleading.
Steven Avery is an interesting case indeed. Do you know where I could get the electropherograms from the case?

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These behaviors are object lessons in how not do forensic science or any other science. The defense in the present case should have asked Professor Murphy or any of the other people whom I have mentioned to testify to such problems.
As I said (repeatedly), an act of malice from within the laboratory cannot be discounted. This is a better explanation than a random failling with no precendens.

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Old 28th July 2020, 02:38 PM   #124
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faking the negative controls

Originally Posted by McHrozni View Post
Now look, "faked" is a different topic entirely. If the laboratory is routinely faking their results, that's a good enough reason to throw all their results out without even examining them. The assumption I make is the laboratory is not deliberately skewing the results in their favor and working in good faith.


Steven Avery is an interesting case indeed. Do you know where I could get the electropherograms from the case?

McHrozni
Replacing the true electropherogram with another, in order to misrepresent the negative control as being clean is a class of misbehavior that one should distinguish from either evidence tampering or carelessly cross-contaminating samples IMO. For example it might be motivated for reasons such as the fact that re-running a whole batch would cost time and money. Another reason is that all of the sample might have been consumed. I don't disagree that it is a serious matter.

I was not able to find electropherograms for the Avery case, but I did find some useful information, which I put into comment #99 in the Avery/Dassey thread.
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Old 29th July 2020, 08:17 PM   #125
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case of Gary Leiterman

In her book Inside the Cell, Professor Erin Murphy wrote (p. 57) "Leiterman's sample came into the laboratory on February 22, 2002; the evidence in Ruelas's case was processed the day before. Leiterman's sample was first analyzed between July 17 and July 23; Ruelas's reference sample was submitted on July 19 and then sent to an outside lab for testing. The Mixer evidence was processed at the lab between March 26, 2002 and April 9, 2002"

Ruelas's DNA on one of the Mixer items is an obvious case of laboratory contamination; that the same might be true of Leiterman's DNA has been pointed out both by Dr. Kessis and Professor Krane.
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Old 29th July 2020, 08:23 PM   #126
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the cold case of Jane Durrua

"Two years after Bellamy’s arrest, investigators discovered that evidence from the murder scene had been contaminated by DNA from [Jerry] Bellamy, whose genetic sample was being tested at the same lab in an unrelated case. He was freed. Another man ultimately was arrested but died before trial." Link. I also dealt with this case briefly at my blog. Unfortunately, at leas one of the links there is dead.
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Old 20th September 2020, 10:56 AM   #127
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Verdict is due on Tuesday.
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Old 20th September 2020, 12:02 PM   #128
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comparison to the Swearingen case

In the Larry Swearingen thread we discussed the laboratory's claim that a particle of dried blood contaminated the fingernail sample of the victim; there was no evidence of this, but it was convenient for the prosecution's case. I am puzzled that laboratory contamination is asserted to be rare in one case and likely in another.
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Old 21st September 2020, 12:35 PM   #129
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Originally Posted by Chris_Halkides View Post
In the Larry Swearingen thread we discussed the laboratory's claim that a particle of dried blood contaminated the fingernail sample of the victim; there was no evidence of this, but it was convenient for the prosecution's case. I am puzzled that laboratory contamination is asserted to be rare in one case and likely in another.
I was wondering about that too. I don't know if there are any reasonable grounds for thinking the likelihood of contamination would be different in the two cases, versus confirmation bias.

I did try thinking about how to get some estimate of probability of contamination in the Claremont case and how it would work in a likelihood ratio compared to this one, looking at the Leiterman case, but gave up on it for the moment as it was doing my head in.

I got the dates a bit mixed up; verdict is actually due on Thursday.
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Old 22nd September 2020, 12:45 AM   #130
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Originally Posted by Elaedith View Post
Verdict is due on Tuesday.
Thursday.
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Old 23rd September 2020, 06:56 PM   #131
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Guilty of two charges but not guilty of killing Sarah Spiers. I will post a link when a good one comes up.
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Old 23rd September 2020, 06:59 PM   #132
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https://www.news.com.au/national/cou...b38c6241f450a2

In a bombshell verdict, the 51-year-old Telstra technician accused of being the Claremont serial killer has been found guilty of two of three murders of young women in 1996 and 1997.


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Bradley Robert Edwards has been found guilty of the murders of Jane Rimmer and Ciara Glennon, but was found not guilty of the murder of Sarah Spiers, the first woman to be abducted from Claremont’s night-life strip in January 1996.

It is a double blow to Ms Spiers’ family, who have been waiting almost a quarter of a century for an explanation of what befell the 18-year-old, whose body has never been found.

The shock decision came over two months after the conclusion of a judge-alone trial which sat for 95 days over seven months and cost the Western Australian justice system $11 million.
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Old 24th September 2020, 07:49 AM   #133
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Originally Posted by lionking View Post
https://www.news.com.au/national/cou...b38c6241f450a2

In a bombshell verdict, the 51-year-old Telstra technician accused of being the Claremont serial killer has been found guilty of two of three murders of young women in 1996 and 1997.
It seems like a just verdict to me. As Supreme Court Justice Stephen Hall noted, the fibre and DNA evidence together sealed Edward's fate on Jane Rimmer and Ciara Glennon.

As sad as it is for the Spiers family, the absence of any direct evidence pointing to Edwards and only the mere coincidence that she disappeared from the same area at around the same period of time meant that the Justice Hall could not convict Edwards of the Sarah Spiers murder.
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Old 24th September 2020, 03:10 PM   #134
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Originally Posted by psionl0 View Post
It seems like a just verdict to me. As Supreme Court Justice Stephen Hall noted, the fibre and DNA evidence together sealed Edward's fate on Jane Rimmer and Ciara Glennon.

As sad as it is for the Spiers family, the absence of any direct evidence pointing to Edwards and only the mere coincidence that she disappeared from the same area at around the same period of time meant that the Justice Hall could not convict Edwards of the Sarah Spiers murder.
Yes I agree. It took a long time for the judge’s decision and it seems sound.
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Old 1st October 2020, 04:06 PM   #135
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I was reading the closing arguments in the last days of the trial, and I noticed Justice Hall was seemed quite open about indicating which way his thoughts were going. He appeared to reject some statements of the defence regarding the DNA sample, and was pressing the prosecution for reasons why he should accept it as proven BARD that the person who murdered Ciara Glennon and Jane Rimmer also murdered Sarah Spiers, rather than just being highly likely.

I am still puzzled by the lack of a robust defence (in terms of calling experts) to challenge the DNA and fibre evidence.
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Old 1st October 2020, 05:27 PM   #136
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you are not the only one

Originally Posted by Elaedith View Post

I am still puzzled by the lack of a robust defence (in terms of calling experts) to challenge the DNA and fibre evidence.
I discussed this case with someone with far more experience in DNA and fiber evidence than I have, and that individual was also quite puzzled.
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Old 13th October 2020, 04:51 AM   #137
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Edwards was convicted of attacking a social worker inside Hollywood Hospital in 1990. He apparently attacked her in her office without warning from behind, and tried to force a gag into her mouth. Hollywood hospital is opposite Karrakatta cemetery, the site of the 1995 rape Edwards confessed to at trial. I believe police always suspected this rape was connected to the Claremont murders, even before any physical evidence, due to the location and manner of the abduction. It seems a significant oversight that nobody connected Edwards' assault conviction to this rape, at the time or even more so after the murders in the next two years. He was only convicted of common assault, although he was ordered to undergo a program for sex offenders, so obviously somebody recognised something rather more sinister in the attack.

This might have been related to the obsession the police had with going after the wrong man.

Another strange aspect is that Edwards kept his job at Telstra, after being convicted of assaulting a woman while working for them as a technician.
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