CBI finds DNA scientist manipulated data

[smartcooky]

I have worked in a lab, and there is zero risk of cross contamination if you follow a protocol. Furthermore, you split your sample before you do anything, keeping as much of the original as you can and test only from a fraction. That way, you can and will retest before submitting a positive result, as well as leave enough for someone else to repeat the test.

If you need to rush things, you can mix fractions of all samples, and test the mixture - if that doesn't match, you only have to do that one test to get a negative.

Ok, but if you want to be sure that something like the subject of this thread doesn't happen, then surely you would have to ensure that any testing of a second split from the remaining sample MUST be done by a different lab tech.

I still think the best option with the fewest questions is to send a second sample to a different lab for parallel testing. That means a different lab tech, and different equipment, and it is certainly cheaper than testing four samples at the same lab.

 

[novaphile]

A double blind test? Would that not create a chance for contamination?

I have seen arguments that all forensic laboratories should be secretly tested, frequently, to establish the rate of error by laboratory.

Those which perform poorly should be tested more frequently.

Similarly, DNA swab tests should always travel in pairs, one used and one not used, and both tested for DNA.

The problem in Germany (IIRC)* where all DNA swabs had been contaminated in the original packaging facility, would have been picked up much earlier if that DNA was found in routine testing of unused collection material.

Edited to add:

* Austria, France and Germany: https://en.wikipedia.org/wiki/Phantom_of_Heilbronn

 

[dann]

Are you sure you want to go with this?

A man rapes and murders a young girl. The man's seminal fluid is found on and inside the girl's body. Its is the only evidence found and it is only evidence they have.

How about now? Still inadmissible?

Your example mimics that of a biased detective or prosecutor: Even before there's any real case, you have decided that the man has done what you have said he has done: raped and murdered a woman.

That is not how a real-life investigation should take place:
1) A body of a woman has been found.
2) The forensic investigation determines that she was raped and killed.
3) Seminal fluid is found.
4) In DNA registers investigators find a man with the same DNA.

The story of a Danish serial rapist and killer: Marcel Lychau Hansen (Wiki)
After his conviction, he sent a sample of his own sperm to one of his sons and tried to convince him to rape a woman and use the sample to make it seem as if there was another rapist, still on the loose, with the same DNA.

There is no reason to assume that another rapist/killer couldn't use a similar trick: Leave behind DNA from somebody else at the crime scene. As The Great Zaganza wrote: "It's trivially easy to introduce foreign DNA into your own crime scene, even in case of rape." (I wouldn't call it trivially easy, but it obviously can and probably already has been done.
In your scenario where "Its is the only evidence found and it is only evidence they have," they would convict the wrong guy.

There are also cases like this one: Framed for Murder by His Own DNA (Wired, April 19, 2018)

Marcel Lychau Hansen also sent samples of his own spit and hair to his son to be used to lead the investigators astray.

 

[Chris_Halkides]

Negative controls in DNA profiling

NBC News reported that "she interfered with controls". There is an article in The Champion by William Thompson about DNA called "Tarnish on the Gold Standard." IIRC he said that the negative controls were the most common form of tampering with DNA evidence. As Donald Riley pointed out, negative controls cannot detect every contamination event; they can find gross but not sporadic contamination.

 

[smartcooky]

Your example mimics that of a biased detective or prosecutor

Nope! You couldn't be more wrong if you tried!

"A man rapes and murders a young girl" is stated, by me, as a fact before the narrative, not as an assumption or a conclusion from an investigation.

It is the equivalent of stating "In the vast prison of Auschwitz, the Nazis had shackled their victims, starved, tortured, and murdered millions of innocent souls." - the opening line of "The Gulag Archipelago" by Aleksandr Solzhenitsyn.

Only I get to decide what my words mean and how they are to be interpreted, not you!

 

[The Great Zaganza]

Too bad Courts don't have the same level of certainty.

 

[Chris_Halkides]

stay tuned

From what I can gather, this is an ongoing investigation; therefore, details are not being released to the general public.

 

[Suddenly]

No, I still think Roboramma's idea to send the samples off for parallel independent testing by a separate lab is the best solution.

A forensic crime lab should not be under the law enforcement chain of command and should be a wholly independent arm of the government with a board including representatives nominated both by the AG's office and the public defender services who then agree upon actual scientists (not forensic technicians; phd types in relevant fields) to join them.

Even then allow a defendant to have their own retained expert either retest material or closely observe testing.

As to double blind that can be done at the data profile level. If different technicians are independently doing the testing of samples to create the profiles that eliminates a whole bunch of opportunities for chicanery.

 

[Suddenly]

This has some similarity to the case of Charles Smith (pathologist)^WP here in Ontario. Though the results of his "errors" were more obviously serious.

Smith diagnosed every baby death that came to him as a result of "shaken baby syndrome". This lead to multiple parent convictions and the removal of children from their parents.

After it was all over:

When it comes to forensic "science" DNA is the least of our problems, really.

It's gets all the pub but a lot of what goes on in a forensics lab is about as sound as astrology. I've seen handwriting analysis reports that were basically some guy with a sociology degree from 30 years who looks at two samples and says they look the same. He's an "expert" because he completes the lab's workbooks and dresses this up in fancy language.

This stuff really needs to not be under the thumb of the cops.

 

[Gord_in_Toronto]

When it comes to forensic "science" DNA is the least of our problems, really.

It's gets all the pub but a lot of what goes on in a forensics lab is about as sound as astrology. I've seen handwriting analysis reports that were basically some guy with a sociology degree from 30 years who looks at two samples and says they look the same. He's an "expert" because he completes the lab's workbooks and dresses this up in fancy language.

This stuff really needs to not be under the thumb of the cops.

Exactly! I have watched enough true crime shows to know the police can get fixated on a suspect to the exclusion of all contrary evidence and reason. A dispassionate civil body is needed for purposes of quality control.

 

[attempt5001]

A few points from someone who has worked in a lab quite a bit.

There will always be "other DNA" samples incorporated into the test protocol, which are known as positive controls. These are likely purchased standards, not samples from volunteers. Also, analyses will be carried out in batches, not for one individual at a time. As Zaganza says, batch protocols that include blanks, replicates, positive controls, negative controls, spikes (and standard curve samples if there is a quantitative output) are all used to monitor for contamination or other false positive or false negative outcomes. Furthermore, accredited laboratories (which would be required for this sort of analysis) are required to participate in inter-lab proficiency testing, to ensure that they continue to demonstrate capability to perform the accredited tests within allowable tolerances for accuracy and precision. Accreditation also includes verifying and documenting analyst competencies.

None of this protects against a deliberate cutting of corners, although data trails are automatically saved and not accessible to lab staff, which is probably how this problem was identified and is being followed up on.

This report is concerning for sure, but unless results were falsified, it's unlikely that the outcome would actually result in incorrect outcomes or convictions.

Not sure I buy into the idea that it's trivial to contaminate a crime scene in a typical sexual assault scenario either. Conceivable, sure, but carrying around a spare vial of genetic material to spike the crime scene with seems like a pretty rare likelihood.

 

[novaphile]

A few points from someone who has worked in a lab quite a bit.

There will always be "other DNA" samples incorporated into the test protocol, which are known as positive controls. These are likely purchased standards, not samples from volunteers. Also, analyses will be carried out in batches, not for one individual at a time. As Zaganza says, batch protocols that include blanks, replicates, positive controls, negative controls, spikes (and standard curve samples if there is a quantitative output) are all used to monitor for contamination or other false positive or false negative outcomes. Furthermore, accredited laboratories (which would be required for this sort of analysis) are required to participate in inter-lab proficiency testing, to ensure that they continue to demonstrate capability to perform the accredited tests within allowable tolerances for accuracy and precision. Accreditation also includes verifying and documenting analyst competencies.

None of this protects against a deliberate cutting of corners, although data trails are automatically saved and not accessible to lab staff, which is probably how this problem was identified and is being followed up on.

This report is concerning for sure, but unless results were falsified, it's unlikely that the outcome would actually result in incorrect outcomes or convictions.

Not sure I buy into the idea that it's trivial to contaminate a crime scene in a typical sexual assault scenario either. Conceivable, sure, but carrying around a spare vial of genetic material to spike the crime scene with seems like a pretty rare likelihood.

Re the latter...

Apparently DNA replication is quite easy to do with temperature controlled equipment, and it has been done with a kitchen stove and a thermometer.

So making a batch of someone else's DNA is within the realms of possibility, especially for someone who has access to a suitable lab where DNA replication is already being done.

From there, all that is needed is a squirty bottle.

I'm surprised that this hasn't happened.

I'm biased because I know people who perform DNA replication every day, and know that they're more than capable, but fortunately, they're not criminals.

 

[Chris_Halkides]

anomalies and more

"The agency has not explained the specific anomalies found in Woods’ DNA testing or offered any detail about how they occurred. But the budget request notes that the re-testing could reveal situations in which prior “testing by the former scientist was inaccurate” and that the re-testing could create “substantial evidence” to retry prior criminal cases." Greely Tribune

If a forensic worker takes a reference sample and treats it as if it were a questioned sample, then that is surely a serious infraction. Missy Woods has been alleged (not in this article) to have done this.

 

[smartcooky]

When it comes to forensic "science" DNA is the least of our problems, really.

It's gets all the pub but a lot of what goes on in a forensics lab is about as sound as astrology. I've seen handwriting analysis reports that were basically some guy with a sociology degree from 30 years who looks at two samples and says they look the same. He's an "expert" because he completes the lab's workbooks and dresses this up in fancy language.

This stuff really needs to not be under the thumb of the cops.

And yet it was primarily handwriting analysis that brought down Ted Kaczynski, the Unabomber.

To be clear, proper handwriting analysis is not just some guy looking at two sample sentences of handwriting and trying to decide if they are by the same person. That is the extreme simplifications you see on TV police procedurals because they only have 45 minutes to tell the story. Actual analysis usually requires a LOT of samples, in which use of language, style of prose, spelling, grammar and phraseology all contribute to the comparison. In Kaczynski's case, his manifesto (which he has publicized) was compared with letters and writings given to the FBI by his younger brother David.

Proper handwriting analysis is sound science, not pseudo science!

 

[smartcooky]

Re the latter...

Apparently DNA replication is quite easy to do with temperature controlled equipment, and it has been done with a kitchen stove and a thermometer.

So making a batch of someone else's DNA is within the realms of possibility, especially for someone who has access to a suitable lab where DNA replication is already being done.

From there, all that is needed is a squirty bottle.

I'm surprised that this hasn't happened.

I'm biased because I know people who perform DNA replication every day, and know that they're more than capable, but fortunately, they're not criminals.

The problem with this is, what are you going have that DNA masquerading as? You can't just put it in a squirty bottle and spread it around a crime scene. Whatever medium it is in, such as a saline solution, or distilled water, is also going to be detected.

This DNA of yours has to actually be in something that came from a person, like blood, or semen or sweat or epithelials. If you contaminate those things with your replicated DNA, those things will still contain their original DNA, so at best, all your faked evidence is going to be an admixture. The fakery would be obvious to a year-one student of forensics.

IF you unfuse blood

 

[attempt5001]

Agreed with smartcooky's points above. And the idea that DNA replication is a simple, stovetop procedure is an over simplification as well. It's true that once all the proper ingredients are prepared and mixed, the amplification process is a simple thermal cycling pattern (temp A for duration X, temp B for duration Y, temp C for duration Z - repeat), but I think novaphile's contacts are glossing over a lot of technical details. You have to start with an isolated and purified DNA sample for starters and people doing routine DNA replication (as I have also done, albeit many years ago) are typically working with constructed DNA plasmids, not just a sample of someone's entire genome extracted from some hair or fluid, which is not a simple, at home, process. You also need to design and manufacture (or order commercially) primers, which are short DNA sequences that anneal to the start point for replication (typically in both the 3' and 5' directions since DNA is two-stranded), you also have to purchase and prepare oligonucleotides solutions (which are not cheap) in the proper manner and concentrations to provide the base building block materials for replication. You then have to store and transport the solution in buffers and at temperatures that ensure it's stability. So not trivial at all.

Even the idea presented above of someone trying to ship their own genetic sample out of prison and have it planted at another crime scene to fool the experts into thinking there is another person with the same DNA on the loose is flawed. The likelihood of that is so statistically improbable that the only reasonable assumption would immediately be the correct one, that the sample had come from the same person.

 

[attempt5001]

(and I forgot to mention the requirement for purchasing, storing, preparing and using the actual enzymes that mediate and catalyze the process of knitting together the nucleotide building blocks. As I mentioned, it's been a while since I've done this work.)

 

[lobosrul5]

1. Do you have any idea how much DNA testing costs? Well, now multiply by four.

2. Who is going to volunteer their DNA for these three additional samples to be tested by the police lab?

3. Keep in mind the fact that these samples will be evidence related to the case (evidence as to the veracity of the target DNA) and all evidence has to be retained for some period of time after the case is done. This means the volunteers' samples and the results are going to be in an evidence locker somewhere, and if the case is never solved, that could be decades. How are you going to guarantee to those people that their samples and tests will NEVER be retained and later used against them?

No, I still think Roboramma's idea to send the samples off for parallel independent testing by a separate lab is the best solution.

Just getting back to this.

1. ... the fact that it will cost more is no reason for the state to abrogate its duties to use factual evidence.
2. Deceased people perhaps? Sort of like a donate your body to science deal.
3. See above.

 

[Chris_Halkides]

Laboratory reform

This stuff really needs to not be under the thumb of the cops.

This is too important a point not to highlight. A recent job posting reads, "Lead a dedicated team of forensic scientists in our state-of-the-art lab. Leverage their expertise to deliver critical evidence, helping detectives solve crimes and secure convictions. Champion justice for victims through timely, accurate analysis." The proper role of a forensic expert is not to be an advocate for the prosecution or the defense. His or her role is to educate the trier of fact. Much ink is spent on the bad apples in forensic science; more ink should be spent on fixing its culture. One reform is to remove labs from the law enforcement chain of command. Calls for this go back at least as far as the Lindy Chamberlain case.

 

[smartcooky]

This is too important a point not to highlight. A recent job posting reads, "Lead a dedicated team of forensic scientists in our state-of-the-art lab. Leverage their expertise to deliver critical evidence, helping detectives solve crimes and secure convictions. Champion justice for victims through timely, accurate analysis." The proper role of a forensic expert is not to be an advocate for the prosecution or the defense. His or her role is to educate the trier of fact. Much ink is spent on the bad apples in forensic science; more ink should be spent on fixing its culture. One reform is to remove labs from the law enforcement chain of command. Calls for this go back at least as far as the Lindy Chamberlain case.

I agree, and the testing should be blind. The independent lab should not know who the samples they are testing comes from or what case it is related to.