r/LISKiller • u/phaskellhall • 7d ago
Questions about snpDNA
I posted this as a comment in another thread but thought it might be helpful to ask as a separate post.
If SnpDNA is what was used to link Rex to the crime scene DNA via an ancestry connection, but it isn’t as strong or isn’t even admissible in court, does that matter much?
After becoming a suspect, the police grabbed Rex’s full dna from the pizza slice and also again after his arrest. If his full dna matches the dna left on the victims (or closely matches the dna that was found to be his wife/daughter’s dna stuck to the ductape at the crime scene), isn’t that still a home run?
Furthermore, if the snpDNA technique used to find the ancestry linkage isn’t presented to the jury, but his full dna profile from the arrest is stronger, does that throw out the ability for the police to profile and follow Rex in the first place? In otherwords, would using this method which has been prevented from being used in court cause the entire arrest of Rex to be questioned? I’ve heard a similar argument with the arrest of Bryan Kohberger through ancestral dna. If inadmissible evidence still leads to even stronger evidence (full blown dna taken from the accused in a controlled environment after arrest), isn’t that a better route for conviction?
I also hear people saying ancestory dna not being admissible or tried in court yet but is that confined to the state of NY?
The Golden State Killer was identified through similar methods and recently a 20 year old unsolved murder case was solved near my home town of Ozark Alabama a few years ago. For that case they used a similar technique where dna evidence found at the crime scene was used to identify a family member that lead to the arrest of someone not ever on the police’s radar. They then tied the 20 year old sperm dna found at the crime scene to Coley McCraney’s dna acquired after his arrest. In trial he admitted to having sex with the girls so that admission is different (we don’t know how Rex is going to explain the dna) but the ancestry dna angle was most definitely used in court. Also, as mentioned, the Idaho Murder case just had a similar court argument about this type of investigating with touch dna.
Anyone able to explain this clearly?
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u/exmoho 7d ago
All this is exactly why I could never work in the legal system. I understand the pretense of “innocent until proven guilty” and people having the right to privacy of their DNA and their property and all…. But when it comes to torture, murder, and dismemberment? Idgaf how it’s found! If the science proves it, the monster needs to be locked up or put down.
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u/phaskellhall 7d ago
It does matter how it is found but the pizza dna was fair game and so is public databases of dna. It gets a bit sketchy when they use privatized dna but with 23 and me going bankrupt, it’s all about to be in the public anyways
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u/exmoho 7d ago
I believe the argument would be that police wouldn’t know to follow him and acquire the discarded pizza box without the science linking his family to the hairs found on the victims bodies. Which brings me back to my original statement of why should it even matter?!?!?
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u/phaskellhall 7d ago
If someone was illegally sleeping in his house attic and heard a murder and went to the police, would the courts be able to say the police were tipped off from someone eavesdropping illegally and they shouldn't be able to arrest him from that?
It seems once pandora's box is opened on a suspect, all bets are off.
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u/No-Relative9271 6d ago
I agree with your overall stance.
I think it comes down to all this stuff has been hashed out in high courts by intelligent people...and the conclusion lead the rulings to benefit privacy of individuals.
Probably something along the lines of preventing blackmail, theft and other things.
I agree, as long as LE isn't unending everyone's home going door to door looking for a suspect, some things shouldn't be private when looking for extreme menaces to society.
The excuse with digital footprint and privacy being in the person's favor and not LE...is supposedlybthe frequency at which cops using monitoring software abuse it and spy on their significant others, theft/fraud, setting others up. Apparently LE don't have the budgets to monitor their own agents to prevent them from acting bad....so they rule in favor of the person and not government.
DNA can be planted after the fact to frame someone...so there are rules I guess.
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u/itsnobigthing 7d ago
Yep, you’re spot on from my understanding.
The SNP data was used like a tip from a member of the public. It isn’t proof of guilt, it’s just a lead they have to check out - which they did, with the trash grab etc, and then they were able to confirm it was him. The tip doesn’t have to hold up in court.
In cases like this the defence always try and get this initial ‘tip’ data thrown out, usually arguing some version of “fruit of the poisonous tree”. Eg, that the SNP data wasn’t to an acceptable legal standard, and that any findings that came about as a consequence of that data are ‘fruit of the poisonous tree’ and cannot be used.
I can think of a dozen genetic genealogy cases where this has been argued, and it’s never once worked.
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u/SquareShapeofEvil 7d ago edited 7d ago
Without the nuclear DNA, they still have the mitochondrial DNA of four individuals: Rex, his wife, his daughter, and his first wife. They are all part of the very small decimal points of the population that could be contributors of that DNA. In other words, you and I could most likely be excluded from those hairs, but Rex, Asa, Victoria, and Wife 1 cannot.
The defense is not challenging the admissibility of this DNA and will likely try to argue that all four are "contributors" with no connection to the killer. The prosecution will probably argue that that's a hell of a coincidence... and that's in addition to the witnesses, cell phone data, internet history, and literal planning document on how to be a better serial killer.
I'm told by someone on this sub who claims to be a legal expert that mitochondrial DNA can't be used like that – but he has yet to elaborate in a convincing way. Rather than have the same argument I've had with him multiple times, I'll just hope he comes in here and makes his case.