5 ms·

I don't think these are typically used (or could be used) to convict someone, I think it's mostly used to guide investigations.

by foota 7y ago

astura 7y ago
This is correct, it's used to find suspects, not to convict anyone.
- geggam 7y ago
  AKA fishing
  - gbrown 7y ago
    If done right, spear fishing. I'm a privacy guy, but the science really is there to use DNA to narrow a list of suspects. You can't say the same for much of forensic science, or for that matter mass surveillance technologies.
    - tareqak 7y ago
      However, the list of suspects can still lack the actual criminal(s), but still contain an innocent with poor, but true alibi.
      - tbyehl 7y ago
        Here's an actual case of an innocent person who faced charges and a high probability of losing their freedom due to DNA transference: https://www.wired.com/story/dna-transfer-framed-murder/ https://www.wired.com/story/dna-transfer-framed-murder/ The take-away is that shed skin cells containing DNA can migrate and a DNA match from that type of evidence shouldn't be relied on as proof of anything. To my view, the combination of DNA transference, advancing DNA collection / analysis techniques, the mere existence of DNA databases, and familial searches are absolutely terrifying.
        gbrown 7y ago
        Good counterpoint, definitely an issue. When the police find macroscopic quantities of bodily fluids, however, it would seem to be madness not to use the evidence.
        tbyehl 7y ago
        Absolutely. I do question if society is better off catching a few more criminals through these databases and familial matching vs the potential for innocents to be imprisoned based on nothing more than a DNA match against skin cells. I'm also not too fond of the idea of my relatives' DNA being used to draw suspicion to another relative just because someone's DNA wound up in a database. To me it's just another one of those things (ALPRs, all the compilations of "it's just metadata") that erode our privacy and give the state a great deal of power for relatively little benefit to the people. All crimes don't get solved, all criminals don't get caught, and in a society where everyone's a law-breaker because there are too many laws to know them all and so many of them are dumb, that's how things should be.
  - BurningFrog 7y ago
    "Fishing" in police work is kinda the opposite: You investigate someone, hoping to find some law they might have broken. This is trying to find out who committed an already known serious crime. That's just "police work", in my view.
    - jacquesm 7y ago
      Except of course that possibly the only link between the suspects and the crime is the DNA, they may not have committed anything. But once such a suspect is lined up the search is over and all that will happen is to look for confirmation rather than exculpation.
      - BurningFrog 7y ago
        Any suspect can always be innocent. There is nothing special about DNA evidence that makes it worse or better in that regard.
    - geggam 7y ago
      You dont have a warrant to find those peoples things. Get a warrant before searching for each persons DNA, not search each persons DNA then get a warrant
monocasa 7y ago
Why wouldn't they be allowed to be used? Anything that guides an investigation is supposed to be admissable evidence or else you get into fruit of the poisonous tree territory, which is illegal. Not saying it wouldn't happen still, but they wouldn't be talking about using it in that case. It'd be like with stingrays where they publicly claim that they got a tip from a confidential informant and drop cases on anyone who gets close to the truth so the never actually get a judge to tell them they can't do it.
- brownbat 7y ago
  > Anything that guides an investigation is supposed to be admissable evidence or else you get into fruit of the poisonous tree territory, which is illegal. Slight correction here. The FPT doctrine makes it so most[0] evidence obtained illegally cannot be admitted. It doesn't work in reverse, it does not imply that all inadmissible evidence is illegal. For example, the first half of many investigations is full of inadmissible hearsay, before you narrow in on what happened and find the people who actually saw something and can testify. There's nothing wrong with talking to people to figure out who knows things, and see how stories changed when they were told to different people, so you can more fully understand what happened. How this applies to your main question -- It might be very difficult to use a DNA database company results in a US court because you might have to involve a ton of witnesses to vouch for every part of the process. Suppose the defense asked, "But how do we know the post office didn't mix up different samples that day!?" You would be forced to either (a) have the USPS provide testimony establishing a full chain of custody, or (b) just test the defendant now to verify the match. It will always be easier to do (b), so I'd guess[1] everyone just skips to that step. [0] Even FPT has exceptions... [1] Maybe there are other procedural ways to approach this that are more common now, I haven't been involved in cases like these or researched it specifically, my criminal procedure knowledge is getting really dated so I might be wrong here.
  - vageli 7y ago
    > > Anything that guides an investigation is supposed to be admissable evidence or else you get into fruit of the poisonous tree territory, which is illegal. > Slight correction here. > The FPT doctrine makes it so most[0] evidence obtained illegally cannot be admitted. It doesn't work in reverse, it does not imply that all inadmissible evidence is illegal. > For example, the first half of many investigations is full of inadmissible hearsay, before you narrow in on what happened and find the people who actually saw something and can testify. There's nothing wrong with talking to people to figure out who knows things, and see how stories changed when they were told to different people, so you can more fully understand what happened. > How this applies to your main question -- > It might be very difficult to use a DNA database company results in a US court because you might have to involve a ton of witnesses to vouch for every part of the process. Suppose the defense asked, "But how do we know the post office didn't mix up different samples that day!?" You would be forced to either (a) have the USPS provide testimony establishing a full chain of custody, or (b) just test the defendant now to verify the match. It will always be easier to do (b), so I'd guess[1] everyone just skips to that step. I never thought of this but it would be surprising if the USPS _didn't_ maintain some sort of chain of custody of mail items, at least at the bag level or whatever unit they use.
2rsf 7y ago
"unbelievable" on Netflix is a good example of such leads- family tree DNA leads to two brothers

I don't think these are typically used (or could be used) to convict someone, I think it's mostly used to guide investigations.

by foota 7y ago

I don't think these are typically used (or could be used) to convict someone, I think it's mostly used to guide investigations.

astura 7y ago

This is correct, it's used to find suspects, not to convict anyone.

geggam 7y ago
AKA fishing
- gbrown 7y ago
  If done right, spear fishing. I'm a privacy guy, but the science really is there to use DNA to narrow a list of suspects. You can't say the same for much of forensic science, or for that matter mass surveillance technologies.
  - tareqak 7y ago
    However, the list of suspects can still lack the actual criminal(s), but still contain an innocent with poor, but true alibi.
    - tbyehl 7y ago
      Here's an actual case of an innocent person who faced charges and a high probability of losing their freedom due to DNA transference: https://www.wired.com/story/dna-transfer-framed-murder/ https://www.wired.com/story/dna-transfer-framed-murder/ The take-away is that shed skin cells containing DNA can migrate and a DNA match from that type of evidence shouldn't be relied on as proof of anything. To my view, the combination of DNA transference, advancing DNA collection / analysis techniques, the mere existence of DNA databases, and familial searches are absolutely terrifying.
      - gbrown 7y ago
        Good counterpoint, definitely an issue. When the police find macroscopic quantities of bodily fluids, however, it would seem to be madness not to use the evidence.
        tbyehl 7y ago
        Absolutely. I do question if society is better off catching a few more criminals through these databases and familial matching vs the potential for innocents to be imprisoned based on nothing more than a DNA match against skin cells. I'm also not too fond of the idea of my relatives' DNA being used to draw suspicion to another relative just because someone's DNA wound up in a database. To me it's just another one of those things (ALPRs, all the compilations of "it's just metadata") that erode our privacy and give the state a great deal of power for relatively little benefit to the people. All crimes don't get solved, all criminals don't get caught, and in a society where everyone's a law-breaker because there are too many laws to know them all and so many of them are dumb, that's how things should be.
- BurningFrog 7y ago
  "Fishing" in police work is kinda the opposite: You investigate someone, hoping to find some law they might have broken. This is trying to find out who committed an already known serious crime. That's just "police work", in my view.
  - jacquesm 7y ago
    Except of course that possibly the only link between the suspects and the crime is the DNA, they may not have committed anything. But once such a suspect is lined up the search is over and all that will happen is to look for confirmation rather than exculpation.
    - BurningFrog 7y ago
      Any suspect can always be innocent. There is nothing special about DNA evidence that makes it worse or better in that regard.
  - geggam 7y ago
    You dont have a warrant to find those peoples things. Get a warrant before searching for each persons DNA, not search each persons DNA then get a warrant

monocasa 7y ago

Why wouldn't they be allowed to be used? Anything that guides an investigation is supposed to be admissable evidence or else you get into fruit of the poisonous tree territory, which is illegal. Not saying it wouldn't happen still, but they wouldn't be talking about using it in that case. It'd be like with stingrays where they publicly claim that they got a tip from a confidential informant and drop cases on anyone who gets close to the truth so the never actually get a judge to tell them they can't do it.

brownbat 7y ago
> Anything that guides an investigation is supposed to be admissable evidence or else you get into fruit of the poisonous tree territory, which is illegal. Slight correction here. The FPT doctrine makes it so most[0] evidence obtained illegally cannot be admitted. It doesn't work in reverse, it does not imply that all inadmissible evidence is illegal. For example, the first half of many investigations is full of inadmissible hearsay, before you narrow in on what happened and find the people who actually saw something and can testify. There's nothing wrong with talking to people to figure out who knows things, and see how stories changed when they were told to different people, so you can more fully understand what happened. How this applies to your main question -- It might be very difficult to use a DNA database company results in a US court because you might have to involve a ton of witnesses to vouch for every part of the process. Suppose the defense asked, "But how do we know the post office didn't mix up different samples that day!?" You would be forced to either (a) have the USPS provide testimony establishing a full chain of custody, or (b) just test the defendant now to verify the match. It will always be easier to do (b), so I'd guess[1] everyone just skips to that step. [0] Even FPT has exceptions... [1] Maybe there are other procedural ways to approach this that are more common now, I haven't been involved in cases like these or researched it specifically, my criminal procedure knowledge is getting really dated so I might be wrong here.
- vageli 7y ago
  > > Anything that guides an investigation is supposed to be admissable evidence or else you get into fruit of the poisonous tree territory, which is illegal. > Slight correction here. > The FPT doctrine makes it so most[0] evidence obtained illegally cannot be admitted. It doesn't work in reverse, it does not imply that all inadmissible evidence is illegal. > For example, the first half of many investigations is full of inadmissible hearsay, before you narrow in on what happened and find the people who actually saw something and can testify. There's nothing wrong with talking to people to figure out who knows things, and see how stories changed when they were told to different people, so you can more fully understand what happened. > How this applies to your main question -- > It might be very difficult to use a DNA database company results in a US court because you might have to involve a ton of witnesses to vouch for every part of the process. Suppose the defense asked, "But how do we know the post office didn't mix up different samples that day!?" You would be forced to either (a) have the USPS provide testimony establishing a full chain of custody, or (b) just test the defendant now to verify the match. It will always be easier to do (b), so I'd guess[1] everyone just skips to that step. I never thought of this but it would be surprising if the USPS _didn't_ maintain some sort of chain of custody of mail items, at least at the bag level or whatever unit they use.

2rsf 7y ago

"unbelievable" on Netflix is a good example of such leads- family tree DNA leads to two brothers