3 ms·

> 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. Sli

> 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.
- foota 7y ago
  I would be super surprised if they _did_ that seems like a massive amount of work for not much gain. Maybe something like logistics (i.e., bag went out for delivery on truck FOO) but I doubt they track everyone that has had access to it.
  - deleted 7y ago
    [deleted]
- Vrondi 7y ago
  USPS has been scanning all mail going through sorting facilities with cameras for years now. All mail is photographed, image goes into a database, image is OCR processed, etc. This is only in recent years, but still. Interesting stuff: https://www.newsweek.com/postal-service-photographs-every-piece-mail-us-shares-agencies-request-it-280614 https://www.newsweek.com/postal-service-photographs-every-pi...
- brownbat 7y ago
  > 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. Probably so. And in civil contract law we almost presume the USPS works more or less like a black box and always functions correctly. I mean, more specifically here, you might not have to question the USPS but might have to question the lab techs, or some company representative, and open up debates about what safeguards they use to prevent samples from getting mixed up. Lots of openings you could avoid by just testing on site, so that will always be easier. You generally just do whatever you can to remove extraneous witnesses to simplify your argument. The subtle trick with US criminal law is that it is still a "testimonial" system. You have to have someone vouch for every piece of evidence. If you take photos of the crime scene you technically have to ask someone questions like, "do these represent the scene of the crime?" ("How would you even know? What makes you an expert on what this place looks like?") Some of this stuff can get waived but in contentious cases you dot your is and cross your ts. Physical evidence is a bit like a hacked on extension of an old oral only court system. You originally just asked a bunch of villagers what happened and hoped they were sufficiently scared of swearing oaths to not lie.

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.

foota 7y ago
I would be super surprised if they _did_ that seems like a massive amount of work for not much gain. Maybe something like logistics (i.e., bag went out for delivery on truck FOO) but I doubt they track everyone that has had access to it.
- deleted 7y ago
  [deleted]
Vrondi 7y ago
USPS has been scanning all mail going through sorting facilities with cameras for years now. All mail is photographed, image goes into a database, image is OCR processed, etc. This is only in recent years, but still. Interesting stuff: https://www.newsweek.com/postal-service-photographs-every-piece-mail-us-shares-agencies-request-it-280614 https://www.newsweek.com/postal-service-photographs-every-pi...
brownbat 7y ago
> 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. Probably so. And in civil contract law we almost presume the USPS works more or less like a black box and always functions correctly. I mean, more specifically here, you might not have to question the USPS but might have to question the lab techs, or some company representative, and open up debates about what safeguards they use to prevent samples from getting mixed up. Lots of openings you could avoid by just testing on site, so that will always be easier. You generally just do whatever you can to remove extraneous witnesses to simplify your argument. The subtle trick with US criminal law is that it is still a "testimonial" system. You have to have someone vouch for every piece of evidence. If you take photos of the crime scene you technically have to ask someone questions like, "do these represent the scene of the crime?" ("How would you even know? What makes you an expert on what this place looks like?") Some of this stuff can get waived but in contentious cases you dot your is and cross your ts. Physical evidence is a bit like a hacked on extension of an old oral only court system. You originally just asked a bunch of villagers what happened and hoped they were sufficiently scared of swearing oaths to not lie.