7 ms·

In Search for Killer, DNA Sweep Exposes Intimate Family Secrets in Italy

80 points by eruditely 12y ago

chatmasta 12y ago
Why stop at a dragnet of 22,000 samples? Why not take DNA samples of every newborn?
- msandford 12y ago
  http://www.imdb.com/title/tt0119177/ http://www.imdb.com/title/tt0119177/
  - deleted 12y ago
    [deleted]
- oh_sigh 12y ago
  Because it is very unlikely that a newborn committed the murder? But really, good question - why not?
  - pdpi 12y ago
    They might commit some crime in 15-20 years' time though.
    - jessaustin 12y ago
      Criminals are actually fairly rare. Once everyone's genetic data is captured it's actually more likely that any given individual will be falsely accused of a crime by lazy cops and prosecutors. "You coughed on a window adjacent to the crime scene, some time in the week before the crime! Guilty!"
      - pdpi 12y ago
        I absolutely agree, and I find this sort of total surveillance mentality completely abhorrent. My comment was mostly meant to illustrate the sort of reasoning that goes with people seriously suggesting that collecting newborn DNA is a good idea.
- judk 12y ago
  What do you mean by "why not" ? In USA, many states and big cities are collecting newborn DNA as well as any human who encounters police or government officials. https://www.aclu.org/free-speech-technology-and-liberty-womens-rights/newborn-dna-banking https://www.aclu.org/free-speech-technology-and-liberty-wome...
- maljx 12y ago
  Blood test of all newborn are saved in Sweden since 1975 for research purposes. The police accessed this data to solve the murder of Anna Lindh (Vice Prime Minister) in 2003.
coldcode 12y ago
Would not likely happen in the US.
- MrBra 12y ago
  Sarcasm?
gph 12y ago
It makes me wonder if in the future there might be false convictions based on DNA evidence, and not from chimeras or inaccurate testing. DNA found at a crime scene has basically come to mean that person is guilty in the public mind (thanks CSI). Even though it's unlikely, it's possible to get some DNA on someone you're near in public who then gets murdered. So you've got DNA on the person, your cell phone is in the area, and you don't have a particular alibi. In most cases that probably means that person is guilty, but I can imagine a number of cases where the person could just be in the wrong place at the wrong time. From the article it sounds like from where the DNA was located and other corraborating evidence that this guy is guilty. But I'm glad the article ended by saying some of the geneticists weren't condemning the accused based on the DNA evidence alone. I hope that type of thinking expands into the wider public.
- smtddr 12y ago
  I wonder about this all the time. Sometimes I comb my hair, or bite my fingernails. What if part of it fell on the floor and some random person steps on it. Stuck on the bottom of their shoe. A bunch of coincidental stuff comes up and my DNA is tested against a fingernail/hair under victim's shoe... match. I'm doomed. Indeed, I fear the mentality that DNA-match = Guilty. How many people have been sent to jail/put to death based on false DNA results or even accurate but not via the crime they're accused of.
  - rangibaby 12y ago
    > Sometimes I comb my hair, or bite my fingernails. What if part of it fell on the floor and some random person steps on it. Stuck on the bottom of their shoe. A bunch of coincidental stuff comes up and my DNA is tested against a fingernail/hair under victim's shoe... match. I'm doomed. This is a plot point in the film Gattaca. I'd recommend watching it if you haven't already: http://en.wikipedia.org/wiki/Gattaca http://en.wikipedia.org/wiki/Gattaca
  - rl3 12y ago
    >Sometimes I comb my hair, or bite my fingernails. You don't even need to comb your hair to leave DNA all over the place. A normal person will lose 50-100 hairs every day.[0] Also, everyone sheds dead skill cells, and certain dermatological conditions can exacerbate matters. [0] http://www.aad.org/dermatology-a-to-z/diseases-and-treatments/e---h/hair-loss http://www.aad.org/dermatology-a-to-z/diseases-and-treatment...
bcoates 12y ago
“The important fact is that this man’s DNA is the same as the DNA found on Yara,” he said, noting that the odds of anyone else sharing the same genetic profile was “one person out of two billion of billions of billions” or practically nonexistent. This fundamental misunderstanding of statistics really doesn't increase confidence in this investigation. When you go on a fishing expedition across 22,000 suspects, the odds of getting a false positive from one cause or another is nearly one.
- themartorana 12y ago
  Is this true? It feels wrong - that a false positive DNA test is not like picking the right number on a roulette table. Considering the number of bits of information that have to match to be a positive hit in DNA testing, even 22k tests shouldn't hit a false positive. Statistics being what they are, what is the science behind false positives in DNA testing across a fairly large sample set?
  - bsder 12y ago
    In addition, I suspect that once they had a match, they could now try to corroborate with other pieces of evidence. I suspect that you could get a DNA match, by itself, thrown out. However, once you use the DNA to narrow down to "these three" you can probably build up the rest of the evidence you need for a solid case.
    - antirez 12y ago
      The suspect cell phone was attached to the tower where the girl was murdered in the same hours of the murdering, even if the suspect does not reside in the exact same area.
      - rwmj 12y ago
        That's not extra evidence, because they were only testing the DNA of people whose cell phones were in the area. Thus the probability that the suspect's cell phone was in the area is always going to be exactly 1.
eruditely 12y ago
The need for prosecutors to be literate in technical fields such as statistics, probability, and perhaps basic forensics is now necessary. Over-zealous prosecutors are some of the most dangerous individuals that seem to go unchecked.
- venomsnake 12y ago
  Overzealous means - we got a guy, now we must find the crime that fits him best.
teddyh 12y ago
Those referencing Gattaca (1997) here should read The Unreconstructed M (1957) by Philip K. Dick: http://www.sffaudio.com/podcasts/TheUnreconstructedMByPhilipK.Dick.pdf http://www.sffaudio.com/podcasts/TheUnreconstructedMByPhilip...
nicolasp 12y ago
There is a similar case in France (albeit at a much smaller scale), where DNA tests were run on all male pupils and staff from a school in an effort to find the perpetrator of a rape. So far they haven't found a suspect. http://www.theguardian.com/world/2014/apr/13/french-school-dna-testing-rapist-la-rochelle http://www.theguardian.com/world/2014/apr/13/french-school-d... http://www.theguardian.com/world/2014/may/22/french-school-rape-dna-testing-la-rochelle http://www.theguardian.com/world/2014/may/22/french-school-r...

80 points by eruditely 12y ago

chatmasta 12y ago

Why stop at a dragnet of 22,000 samples? Why not take DNA samples of every newborn?

msandford 12y ago
http://www.imdb.com/title/tt0119177/ http://www.imdb.com/title/tt0119177/
- deleted 12y ago
  [deleted]
oh_sigh 12y ago
Because it is very unlikely that a newborn committed the murder? But really, good question - why not?
- pdpi 12y ago
  They might commit some crime in 15-20 years' time though.
  - jessaustin 12y ago
    Criminals are actually fairly rare. Once everyone's genetic data is captured it's actually more likely that any given individual will be falsely accused of a crime by lazy cops and prosecutors. "You coughed on a window adjacent to the crime scene, some time in the week before the crime! Guilty!"
    - pdpi 12y ago
      I absolutely agree, and I find this sort of total surveillance mentality completely abhorrent. My comment was mostly meant to illustrate the sort of reasoning that goes with people seriously suggesting that collecting newborn DNA is a good idea.
judk 12y ago
What do you mean by "why not" ? In USA, many states and big cities are collecting newborn DNA as well as any human who encounters police or government officials. https://www.aclu.org/free-speech-technology-and-liberty-womens-rights/newborn-dna-banking https://www.aclu.org/free-speech-technology-and-liberty-wome...
maljx 12y ago
Blood test of all newborn are saved in Sweden since 1975 for research purposes. The police accessed this data to solve the murder of Anna Lindh (Vice Prime Minister) in 2003.

coldcode 12y ago

Would not likely happen in the US.

MrBra 12y ago
Sarcasm?

gph 12y ago

It makes me wonder if in the future there might be false convictions based on DNA evidence, and not from chimeras or inaccurate testing. DNA found at a crime scene has basically come to mean that person is guilty in the public mind (thanks CSI). Even though it's unlikely, it's possible to get some DNA on someone you're near in public who then gets murdered. So you've got DNA on the person, your cell phone is in the area, and you don't have a particular alibi. In most cases that probably means that person is guilty, but I can imagine a number of cases where the person could just be in the wrong place at the wrong time. From the article it sounds like from where the DNA was located and other corraborating evidence that this guy is guilty. But I'm glad the article ended by saying some of the geneticists weren't condemning the accused based on the DNA evidence alone. I hope that type of thinking expands into the wider public.

smtddr 12y ago
I wonder about this all the time. Sometimes I comb my hair, or bite my fingernails. What if part of it fell on the floor and some random person steps on it. Stuck on the bottom of their shoe. A bunch of coincidental stuff comes up and my DNA is tested against a fingernail/hair under victim's shoe... match. I'm doomed. Indeed, I fear the mentality that DNA-match = Guilty. How many people have been sent to jail/put to death based on false DNA results or even accurate but not via the crime they're accused of.
- rangibaby 12y ago
  > Sometimes I comb my hair, or bite my fingernails. What if part of it fell on the floor and some random person steps on it. Stuck on the bottom of their shoe. A bunch of coincidental stuff comes up and my DNA is tested against a fingernail/hair under victim's shoe... match. I'm doomed. This is a plot point in the film Gattaca. I'd recommend watching it if you haven't already: http://en.wikipedia.org/wiki/Gattaca http://en.wikipedia.org/wiki/Gattaca
- rl3 12y ago
  >Sometimes I comb my hair, or bite my fingernails. You don't even need to comb your hair to leave DNA all over the place. A normal person will lose 50-100 hairs every day.[0] Also, everyone sheds dead skill cells, and certain dermatological conditions can exacerbate matters. [0] http://www.aad.org/dermatology-a-to-z/diseases-and-treatments/e---h/hair-loss http://www.aad.org/dermatology-a-to-z/diseases-and-treatment...

bcoates 12y ago

“The important fact is that this man’s DNA is the same as the DNA found on Yara,” he said, noting that the odds of anyone else sharing the same genetic profile was “one person out of two billion of billions of billions” or practically nonexistent. This fundamental misunderstanding of statistics really doesn't increase confidence in this investigation. When you go on a fishing expedition across 22,000 suspects, the odds of getting a false positive from one cause or another is nearly one.

themartorana 12y ago
Is this true? It feels wrong - that a false positive DNA test is not like picking the right number on a roulette table. Considering the number of bits of information that have to match to be a positive hit in DNA testing, even 22k tests shouldn't hit a false positive. Statistics being what they are, what is the science behind false positives in DNA testing across a fairly large sample set?
- bsder 12y ago
  In addition, I suspect that once they had a match, they could now try to corroborate with other pieces of evidence. I suspect that you could get a DNA match, by itself, thrown out. However, once you use the DNA to narrow down to "these three" you can probably build up the rest of the evidence you need for a solid case.
  - antirez 12y ago
    The suspect cell phone was attached to the tower where the girl was murdered in the same hours of the murdering, even if the suspect does not reside in the exact same area.
    - rwmj 12y ago
      That's not extra evidence, because they were only testing the DNA of people whose cell phones were in the area. Thus the probability that the suspect's cell phone was in the area is always going to be exactly 1.

eruditely 12y ago

The need for prosecutors to be literate in technical fields such as statistics, probability, and perhaps basic forensics is now necessary. Over-zealous prosecutors are some of the most dangerous individuals that seem to go unchecked.

venomsnake 12y ago
Overzealous means - we got a guy, now we must find the crime that fits him best.

teddyh 12y ago

Those referencing Gattaca (1997) here should read The Unreconstructed M (1957) by Philip K. Dick: http://www.sffaudio.com/podcasts/TheUnreconstructedMByPhilipK.Dick.pdf http://www.sffaudio.com/podcasts/TheUnreconstructedMByPhilip...

nicolasp 12y ago

There is a similar case in France (albeit at a much smaller scale), where DNA tests were run on all male pupils and staff from a school in an effort to find the perpetrator of a rape. So far they haven't found a suspect. http://www.theguardian.com/world/2014/apr/13/french-school-dna-testing-rapist-la-rochelle http://www.theguardian.com/world/2014/apr/13/french-school-d... http://www.theguardian.com/world/2014/may/22/french-school-rape-dna-testing-la-rochelle http://www.theguardian.com/world/2014/may/22/french-school-r...