
Relative's DNA from genealogy websites cracked East Area Rapist case - HoppedUpMenace
http://www.sacbee.com/news/local/crime/article209913514.html
======
ninkendo
This is a very interesting issue with sending your DNA to sites like 23andme.
This means that a police officer can get a warrant to submit a DNA sample to
the site, and get back anyone who matches. (Or in this case, their relatives.)

The reason I think it's particularly interesting is that it _passes_ one of
the basic tests I have for whether something should be searchable by law
enforcement: Do they have a target in mind and a warrant to search for that
target? For PRISM and the other things that Snowden warned us about, the
answer was no: the government was doing dragnet surveillance of all sorts of
data warehouses to find people who fit a profile, without knowing who they're
looking for ahead of time. With this, they have to have a DNA sample found at
a crime scene, and they're using that combined with a warrant to do a targeted
search for people with matching DNA. It just happens to be a website that
people send their DNA to, rather than a police database.

So I'm actually inclined to say I think this is ok? But I'm not 100% sure how
I feel yet.

EDIT: ok it looks like this was done not necessarily with a warrant, but with
the officer just submitting the DNA as if they're a customer of the site. But
actually my point still stands if they changed their technique to instead use
a warrant and ask the site directly, not hiding that they were police
officers... it's just that in this case they didn't even need to because it's
so easy to just send others' DNA samples to these sites? It really seems like
the lack of a warrant was a technicality here and could have easily gone the
other way and still got to the same result.

~~~
scarmig
Hmmm. As a consumer, am I allowed to submit someone else's DNA to 23andMe
without their consent?

~~~
fma
Reminds me of GATACCA where the woman kisses a man and the goes to a booth to
submit the DNA to make sure he is a 'good catch'...

~~~
eecc
Yeah and made me wonder if we'll end up having to daily scrub ourselves in an
incinerator...

------
conroy
I was very confused about this. The genealogy website did not probide any
information to law enforcement. Instead, law enforcement uploaded DNA from the
crime scene to the genealogy website.

[https://www.nytimes.com/2018/04/26/us/golden-state-
killer.ht...](https://www.nytimes.com/2018/04/26/us/golden-state-killer.html)

~~~
chatmasta
...and then the genealogy website provided information to law enforcement by
showing profiles of people with similar DNA.

Perhaps that’s the real privacy issue... anyone can find a piece of hair on
the sidewalk, send it to a genealogy website, and identify who it might belong
to and/or any relatives.

~~~
chrischen
23andme requires quite a bit of saliva. They could definitely up the
requirements to decrease the chance of fraud.

~~~
et2o
It's trivial to replicate even very small amounts of DNA. They don't actually
need very much DNA, they just ask for that much to ensure it will work.

~~~
chrischen
Wouldn't they have to replicate whatever medium it is in as well? For example,
if sending in saliva, you'd have to replicate the saliva as well.

~~~
et2o
No need to replicate saliva. The DNA extraction chemistry wouldn't depend on
saliva components.

------
chatmasta
Interestingly it wasn’t even his DNA in the database, but a relative’s. It
just goes to show that there is nowhere to hide. Even if you stay completely
offline, it only takes one relative to log the bulk of your DNA onto the
Internet. Metadata strikes again.

~~~
nasredin
_Literal_ metadata (DNA) _preempts_ this guy from striking again.

~~~
Faark
You usually use obviously beneficial cases to push boundaries. Having your
medical insurance pay one of your relatives for their DNA to re-rate you and
other relatives or other horror scenarios will follow later down the line,
once we've shown willing to give up privacy.

This entire "you share lots of info (DNA) with your relatives, thus they can
screw you with it" is a pretty new issue. I doubt we understand the full
ramifications, yet, and thus i'd prefer caution instead of the government
giving others a green light to screw me in ways i cannot even imagine, yet.

~~~
fixermark
"Family members can screw you via relation" isn't really a new issue. English
Common Law generally moved the legal needle on literally being killed or sent
to jail for the crimes of a relative thanks to the abolition of "corruption of
blood" law, but there are a lot of other ways you can be on the hook for a
relative's actions.

------
vermontdevil
One guy I know sent in his dna to ancestry. He was immediately matched with a
woman as highly likely to be his sister. He was shocked and they connected.
Turns out they are siblings and both adopted at birth. So there’s some upsides
to these sites

Nevertheless hopefully ancestry etc would have sensible policies to protect
peoples’ privacy unleSs a court order is involved.

~~~
txsh
There are other downsides, too.

I have a cousin who found out, in his 50s, after his mother and father had
passed away, that he was not related to anybody in our family. It crushed him.

~~~
frogpelt
[https://www.vox.com/2014/9/9/5975653/with-genetic-
testing-i-...](https://www.vox.com/2014/9/9/5975653/with-genetic-testing-i-
gave-my-parents-the-gift-of-divorce-23andme)

This guy gave his parents the gift of divorce.

~~~
nasredin
Ugh.

The guy has a PhD but writes like a BuzzFeed writer.

Unreadable.

~~~
astura
There's something said about making material accessible to the "everyman" if
you want your material to be widely accessed.

------
curtis
The reporting on exactly how DNA was used to identify the Golden State Killer
is still pretty limited.

It sounds like they submitted DNA from GSK crime scenes to a number of
genealogical sites and got back one or more familial matches. From that match
or matches, they were able to backtrack to a specific suspect.

Once the suspect was identified, they were able to surreptitiously obtain the
suspect's DNA, then they directly tested that DNA against GSK DNA samples, and
were able to confirm the match.

It hasn't been stated directly, but it seems like there is plenty of still-
usable DNA from GSK crime scene evidence, even though it will now be 30+ years
old.

~~~
jopsen
The idea of finding suspects based on DNA is not without problems, is it?

~~~
Chriky
It seems like one of the least problematic ways of generating suspects to me -
what's the issue compared to, say, eye witness testimony?

~~~
arbitrage
Whereas eye-witness testimony is incredibly unreliable, but laypersons
typically believe it to be accurate, the opposite is true with DNA forensic
evidence. The public generally believes it to be infallible, when in reality
it's not always that clear cut.

It should be regarded as another tool in the toolbox, not the be-all and end-
all of criminal forensic investigation.

------
ArcticUnicorn
'As he was being arrested, he told officers he had a roast in the oven. They
said they would take care of it.'

Humans are an odd bunch.

~~~
whatshisface
Arrest isn't conviction, so it's a good thing that officers don't always act
like they're putting away a killer (and that the accused don't always act like
they're about to be put away for life.)

~~~
Rebelgecko
Arrest isn't conviction, but since the topic here is DNA it's worth noting
that in California you can have your DNA taken against your will and put into
a database when you get arrested even if you're never convicted or even
charged with a crime.

~~~
gojomo
Further, in California and most other states, a 'fetal blood spot' is taken
from every newborn and tested for a variety of genetic diseases, and the spot
is retained in some state filing cabinet (or refrigerator?) somewhere. See an
older comment for details & links:

[https://news.ycombinator.com/item?id=6811167#6811805](https://news.ycombinator.com/item?id=6811167#6811805)

Just as there was a state proposition (sponsored by the relatives of one of
this killer's victims) to expand DNA-testing of criminal suspects, a future
policy change could send investigators into those filing cabinets, if the
blood DNA isn't too degraded, to do a broad genetic dragnet for criminal
suspects (or their relatives).

~~~
tehlike
Is there any way to opt out of this?

~~~
gojomo
There's technically some ability for parents to opt-out of the delivery of the
blood spot to the state, by written request before/during the delivery
process.

But that's so discouraged, and the normal process is so automatic and hectic,
that it's very rare. Few even realize the blood-spot permanent-collection is
happening.

There was a proposed bill in 2015 to require signed consent before the
collection, but it was defeated. See very end of:

[https://nakedsecurity.sophos.com/2015/11/12/california-
colle...](https://nakedsecurity.sophos.com/2015/11/12/california-collects-
owns-and-sells-infants-dna-samples/)

------
airstrike
This comment section reads like half the people didn't bother to read the
article or even Google the case and somehow think the police are framing an
innocent man.

~~~
adventured
That's part of it. The other part is that it has become a pop-knowledge meme -
Reddit & Imgur style - that DNA tests are nearly worthless, are almost never a
sound means to convinct someone, and that they mostly just convict innocent
people when used by the police. That immediately becomes the go-to parroted
premise anytime discussions like these occur, without exception. It's bumper
sticker forensic science knowledge.

~~~
azemetre
Well, in the public's defense of being skeptical of "forensic science" has
been a range of outright lying[1] to mystical beliefs that look no different
than shamanism or voodoo[2].

You should also be aware that the Nation Research Council has done a study[3]
on "forensic science" where DNA was the only barely reliable measurement in
the entire field.

These are methods the US Justice Department/Police/Judges/Prosecutors
routinely uses to destroy innocent lives and trick juries. It's not hard to
see how people become skeptical.

I'm not saying this is the case with the capture of the Golden State Killer,
but it's not hard to see how the public lost its trust in these institutions
we hold to be accountable and make choices.

[1] [https://www.washingtonpost.com/local/crime/fbi-overstated-
fo...](https://www.washingtonpost.com/local/crime/fbi-overstated-forensic-
hair-matches-in-nearly-all-criminal-trials-for-
decades/2015/04/18/39c8d8c6-e515-11e4-b510-962fcfabc310_story.html?utm_term=.bf2b4a7470a4)

[2] [https://www.scientificamerican.com/article/can-we-trust-
crim...](https://www.scientificamerican.com/article/can-we-trust-crime-
forensics/)

[3]
[https://www.ncjrs.gov/pdffiles1/nij/grants/228091.pdf](https://www.ncjrs.gov/pdffiles1/nij/grants/228091.pdf)

------
rdl
I'm surprised they are being so public about this (they could have downplayed
it, even if they didn't go full parallel construction.)

This will potentially cause people to be less willing to use sites like this,
and this could have long-term negative public health impact. Plus, it hurts
the commercial businesses.

(My DNA is on record with DOD for personnel recovery purposes, as are most
military/contractor personnel of the past 15 years or so, but I'm not sure how
the actual database works. I suspect in reality it means China, Russia,
Israel, and any other competent infosec adversary also has a full copy of this
database.)

~~~
caf
Will it, though? I would bet most people wouldn't consider _" maybe this will
expose a murderer in my family"_ as a realistic possibility, and even among
those who would, most probably would be OK with that.

~~~
rdl
Murderer in my family, probably not, but what if it is "drug crime in my own
family" or the more likely "expensive medical disorder which will preclude
insurance, employment, dating, etc.". It's still data being used "against" the
user or his relatives.

This long article that someone on Twitter sent me is interesting:
[https://medium.com/matter/23-and-
you-66e87553d22c](https://medium.com/matter/23-and-you-66e87553d22c)

~~~
fixermark
Those are reasonable extrapolations but are outside the purview of the
police's concern. I don't expect they would stop a police chief (let alone a
beat-cop) from bragging about a cool new method for narrowing a suspect list,
because the benefit to other cops knowing about it outweighs the harm to the
companies' bottom lines.

------
fipple
This kind of screening is extremely fucked up because _average people are
terrible statistical reasoners_. A 99.999% accurate DNA test will find mostly
innocent people if applied to a database of tens of millions of people. And
even without corroborating evidence, juries will convict on the DNA because
average people aren’t wired for this kind of statistical reasoning.

~~~
fixermark
The defense will need expert witnesses to explain why genealogical-resolution
matching is unreliable, but any defense attorney worth their salt should have
a stable of such witnesses; the difference between "A 100% correlated match
between DNA at a crime scene and the suspect's DNA" and "An N% correlation
between a suspect's DNA and a suspected relative of the suspect" is pretty
clear even to this layperson.

IANAL, but even without the expert witness, defense should be able to throw
enough doubt for a criminal case defense with a line of questioning that
begins "If the DNA matched to person Q in the DNA database and not to my
client, why is person Q not the one being charged with this crime?" Defense
can then move from there to the observation that the match to a relative in
the database merely narrows the field of subjects to a whole family tree of
relatives of the matched individual.

(Note that in this case, the police used the geneology matches as a tool to
focus suspect list, not as primary evidence in a murder trial. That's more in
the realm of "Looking for everyone in town who buys that brand of cigar" than
in the realm of "Your dad's DNA got you sent to prison!!!").

------
pg_bot
An excerpt from Michelle McNamara's letter to the golden state killer.

The race was yours to win. You were the observer in power, never observed. An
initial setback came on September 10, 1984, in a lab at the University of
Leicester, when the geneticist Alec Jeffreys developed the first DNA profile.
Another came in 1989, when Tim Berners-Lee wrote a proposal for the World Wide
Web. People who weren’t even aware of you or your crimes began devising
algorithms that could help find you. In 1998, Larry Page and Sergey Brin
incorporated their company, Google. Boxes holding your police reports were
hauled out, scanned, digitized, and shared. The world hummed with connectivity
and speed. Smartphones. Optical-text-recognition technology. Customizable
interactive maps. Familial DNA.

I’ve seen photos of the waffle-stomper boot impressions you left in the dirt
beneath a teen-age girl’s bedroom on July 17, 1976, in Carmichael, a crude
relic from a time when voyeurs had no choice but to physically plant
themselves in front of windows. You excelled at the stealth sidle. But your
heyday prowess has no value anymore. Your skill set has been phased out. The
tables have been turned. Virtual windows are opening all around you. You, the
master watcher, are an aging, lumbering target in their crosshairs.

A ski mask won’t help you now.

[https://www.newyorker.com/books/page-turner/letter-to-the-
go...](https://www.newyorker.com/books/page-turner/letter-to-the-golden-state-
killer)

~~~
atomical
What makes Michelle special compared to all these amateur sleuths that thought
they were going to solve the case but didn't?

~~~
scarmig
She wrote a good, comprehensive book that is both well-researched and
accessible.

~~~
atomical
So? The police solved the case.

------
pfarnsworth
I did 23 and Me but under a fake name. It correctly identified me as a 1st
cousin with my cousin, whom I had no idea had already taken the test as well.
It was very very spooky, and I can see how useful this would be for law
enforcement. At some point in the future, you can drastically limit the number
of people to search for based on DNA to a single family tree, if enough people
submit their own DNA. It's scary.

It's exactly like your contact list. Facebook doesn't need you to give them
your phone number. They just need 1 out of your 500 contacts to upload their
entire contacts list so that they get your phone number. The law of numbers is
completely against you and your privacy is already violated completely because
one of your friends did it to you.

------
dexen
To what extent the bone marrow donor databases are subject to the same risk of
police _fishing expeditions_? Do they hold full DNA profile, or just the
fragments relevant to immunocompatibility?

~~~
astura
Of course not.

Unlike ancestry websites, the purpose of bone marrow database is not to
connect users to relatives. Police don't have the ability to send crime scene
data into the bone marrow registry and get back "here's the subject's
siblings." I don't even think you're allowed to meet someone you're matched
with and donate bone marrow to; for at least several years, if not forever.

The police literally uses the website as designed: "here's DNA; get back known
close relatives."

[https://bethematch.org/privacy/](https://bethematch.org/privacy/)

Edit: looks like they used an "open source" genealogy DNA website GEDMatch;
not one of the commercial ones:
[https://www.eastbaytimes.com/2018/04/26/ancestry-23andme-
den...](https://www.eastbaytimes.com/2018/04/26/ancestry-23andme-deny-
assisting-law-enforcement-in-east-area-rapist-case/)

"Lead investigator Paul Holes, a cold case expert and retired Contra Costa
County District Attorney inspector, said his team’s biggest tool was GEDmatch,
a Florida-based website that pools raw genetic profiles that people share
publicly. No court order was needed to access that site’s large database of
genetic blueprints. Other major private DNA ancestral sites said they were not
approached by police for this case."

GED Match describes itself as such - "GEDmatch provides DNA and genealogical
analysis tools for amateur and professional researchers and genealogists."

------
youpassbutter
I've been saying this for years. DNA sites are a goldmine for unresolved cold
cases ( rape, murder, missing persons ) where DNA is available.

In the past, if there was a rape in a city, the cops couldn't force everyone
in the city to give their DNA to find the rapist. Now, everyone in the city is
paying to give their DNA to DNA sites. All cops had to do is submit the DNA of
cold cases to these sites and see if they get a match of any kind ( cousins,
siblings, parents or the suspect themselves ).

------
darkstar999
If law enforcement can make use of a private sector DNA database like this, is
there a good argument against a mandatory national database?

------
JoblessWonder
This is pretty huge. I'm wondering if it is from something like YSearch [1]
where you can just put in any-old Haplotype and see results or if it is from
one of the larger, well known firms like 23AndMe or Ancestry.com.

[1]
[http://www.ysearch.org/search_search.asp?uid=&freeentry=true](http://www.ysearch.org/search_search.asp?uid=&freeentry=true)

------
rgejman
Does anyone have any more information on this? How do the police get access to
DNA from genealogical databases? Do they need a warrant for a specific persons
DNA? Do the police check for matches or does the company?

~~~
Maxious
They used "crime scene" samples and what they are calling “abandoned” DNA from
the suspect ("You leave your DNA in a place that is a public domain” they
don't need a warrant?) [https://www.nytimes.com/2018/04/26/us/golden-state-
killer.ht...](https://www.nytimes.com/2018/04/26/us/golden-state-killer.html)

~~~
conanbatt
This is more than that: it wasnt his dna, it was one of his relatives dna on
the site that got him found.

Im guessing that any relative has a right to divulge his dna and rat out a
blood relative in a situation like this, but I doubt people actually consent
to that use when they are looking at a genealogy site.

~~~
paxys
Well one of the big uses of ancestry services is to find unknown relatives,
so...yay?

------
notadoc
DNA is not infallible, and DNA transfer is so common that DNA "evidence" is
not really evidence of anything at all.

Here's an interesting recent story on this very topic:

[https://www.pbs.org/wgbh/frontline/article/framed-for-
murder...](https://www.pbs.org/wgbh/frontline/article/framed-for-murder-by-
his-own-dna/)

------
DanielBMarkham
I'm really glad they caught the guy.

I am concerned about the way it happened.

They didn't match evidence to a person directly. They matched evidence to a
DNA database to find the person. That sounds like the same thing, but it's
not.

There was no warrant. The DNA database company did not know they were
participating in a law enforcement case. There could be other people (unlikely
but possible) that matched but weren't on file anywhere. People will start
viewing such evidence as "Science!" instead of evidence like all the rest.

Finally, if this okay, we have an economics question. It cost the cops 40 or
50 bucks to catch a serial killer. Well-spent money in my book. But what if
they could catch people for 10 bucks? Or a dollar? What if they could
automatically collect samples and run them without any manual effort?

If this happens -- and I see no reason that it won't -- it won't be just
serial killers. It'll be parking violations, trespassers, urban graffiti
artists -- anybody that can leave DNA. And who's got the money to fight
something like this over a traffic ticket if they get it wrong? People will
just pay up or go to prison.

It's continuing the destruction of our human-powered, adversarial, community-
approved justice system, replacing it with automation and faux certainty.
Catching evil killers is awesome, but the rest of it doesn't seem like such a
good future for my kids or grand-kids.

~~~
astura
Police used an "open source" genealogy DNA website GEDMatch; not one of the
commercial ones:

[https://www.eastbaytimes.com/2018/04/26/ancestry-23andme-
den...](https://www.eastbaytimes.com/2018/04/26/ancestry-23andme-deny-
assisting-law-enforcement-in-east-area-rapist-case/)

>Lead investigator Paul Holes, a cold case expert and retired Contra Costa
County District Attorney inspector, said his team’s biggest tool was GEDmatch,
a Florida-based website that pools raw genetic profiles that people share
publicly. No court order was needed to access that site’s large database of
genetic blueprints. Other major private DNA ancestral sites said they were not
approached by police for this case.

>"“GEDmatch exists to provide DNA and genealogy tools for comparison and
research purposes,” the site states on its policy page. “It is supported
entirely by users, volunteers, and researchers. DNA and Genealogical research,
by its very nature, requires the sharing of information. Because of that,
users participating in this site should expect that their information will be
shared with other users.”

>“If you require absolute security, please do not upload your data to
GEDmatch. If you have already uploaded it, please delete it,” it continues.
“While the results presented on this site are intended solely for genealogical
research, we are unable to guarantee that users will not find other uses.”

------
thelittleone
Great to see justice in this case. On the flip side, privacy treasure trove's
like this may become a tool for targeting non-criminals, for example
classified cases targeting anonymous political activists or similar. It's no
longer their own opsec activists need to worry about. It's all so very
Gattaca.

------
klarrimore
How many other police departments do you think just read this and are
frantically sending in cold case DNA samples?

------
eqtn
Is it legal to search a medical database to get details of people with a
certain genetic disorder?

~~~
astura
"A medical database." _What_ medical database?

You mean, like a database of patient records compiled by a hospital? No, most
countries have laws on how those medical records can and can't be used.

A database of DNA of felons collected by police departments where the DNA is
also tested for genetic conditions? Barring any specific laws preventing that
specific scenario, I don't see why that would be illegal.

------
yani
Let us the police collect this data and ask everyone who is honest person to
add their DNA to it. I have no problem adding my DNA to such resource but when
this data is obtained without my knowledge or permission it is the same as
stealing.

~~~
astura
Looks like that's exactly what they did...

[https://www.eastbaytimes.com/2018/04/26/ancestry-23andme-
den...](https://www.eastbaytimes.com/2018/04/26/ancestry-23andme-deny-
assisting-law-enforcement-in-east-area-rapist-case/)

>Lead investigator Paul Holes, a cold case expert and retired Contra Costa
County District Attorney inspector, said his team’s biggest tool was GEDmatch,
a Florida-based website that pools raw genetic profiles that people share
publicly. No court order was needed to access that site’s large database of
genetic blueprints. Other major private DNA ancestral sites said they were not
approached by police for this case.

>"“GEDmatch exists to provide DNA and genealogy tools for comparison and
research purposes,” the site states on its policy page. “It is supported
entirely by users, volunteers, and researchers. DNA and Genealogical research,
by its very nature, requires the sharing of information. Because of that,
users participating in this site should expect that their information will be
shared with other users.”

>“If you require absolute security, please do not upload your data to
GEDmatch. If you have already uploaded it, please delete it,” it continues.
“While the results presented on this site are intended solely for genealogical
research, we are unable to guarantee that users will not find other uses.”

------
MaikuMori
I guess they produced export which is similar or exact format to the exports
of one of the popular sites and imported it. For example 23andme currently has
DNA day promotion which lets you import ancestry exports. Seems a bit shady to
me.

------
ajudson
I wonder if this sort of method will be challenged and end up in the Supreme
Court.

~~~
acomjean
Some states have banned familial searching. I took a genomics class and the
guest speaker was a forensic scientist, he explained the pros and cons.
Clearly getting these serial criminals off the street has some benifit.

Its been done before. One of the first was the "Grim Sleeper" case with an
arrest in 2010. In that case they used the police database though (california
has dna of all felons.)

[https://en.wikipedia.org/wiki/Grim_Sleeper](https://en.wikipedia.org/wiki/Grim_Sleeper)
"Police had found no exact match between DNA found at the crime scenes and any
of the profiles in California's DNA profile database, so they searched the
database for stored profiles that demonstrated sufficient similarity to allow
police to infer a familial relationship. They found similar DNA belonging to
Franklin's son, Christopher, who had been convicted of a felony weapons
charge. According to Los Angeles District Attorney Steve Cooley, detectives
then used a piece of discarded pizza with Franklin's DNA to make the link. One
Los Angeles undercover police officer pretended to be a waiter at a restaurant
where the suspect ate. He collected dishes, silverware, glasses, and pizza
crusts to obtain DNA.[20] The identification was used to arrest Franklin after
his DNA was obtained and deemed a match.[21] Saliva found on the victims
established a DNA match linking Franklin to the deaths"

------
clarkevans
I do hope the prosecutor is being careful about representing the strength of
DNA evidence as this person was found through a fishing expedition via a DNA
database.

[https://en.wikipedia.org/wiki/Prosecutor%27s_fallacy](https://en.wikipedia.org/wiki/Prosecutor%27s_fallacy)

 _However, if the DNA evidence is the sole evidence against the accused and
the accused was picked out of a large database of DNA profiles, the odds of
the match being made at random may be increased, and less damaging to the
defendant. The odds in this scenario do not relate to the odds of being
guilty, they relate to the odds of being picked at random._

~~~
fixermark
RTA. The relative match was used to narrow the suspect list and focus the
investigation. I don't know the prosecutor is even going to bring up the
ancestry DNA in the trial, and I doubt they will given the much more accurate
direct DNA match they were able to acquire after staking out the suspect's
home.

~~~
clarkevans
Your reply, _" I don't know the prosecutor is even going to bring up the
ancestry DNA in the trial"_, exactly reflects my concern. Are you asserting
that the DNA search and the _" much more accurate DNA match"_ are
statistically independent or that their dependence (overlapping genetic
markers) is not relevant?

P.S. Regarding your _" RTA"_ ... from the Hacker News guidelines at the bottom
of the page, I quote: _" Please don't insinuate that someone hasn't read an
article."_

~~~
fixermark
Quite correct on the guidelines; my error.

I don't know about the statistical independence of the DNA search and the
match on separately-collected DNA directly from the suspect (once a suspect
was found via the DNA search), but I think it's a little irrelevant; as long
as existing laws aren't broken, I understand the court to generally not care
how police became aware of evidence of a crime. Consider the oft-maligned
"Stopped for a broken tail-light but there were drugs in the car" scenario. If
the defendant goes to trial for the drug possession, the broken tail-light
doesn't enter into the trial as evidence (mention of it may enter if someone
asks the arresting officer why they chose to stop the defendant).

Bringing the analogy around to this case: if a DNA relative match narrowed the
field of suspects to the relatives of match candidate X, then the police still
need evidence tying relative Y directly to the crime. In this case, they
subsequently investigated Y and found such evidence. Should the initial scan
of a DNA database for candidate X have been illegal? I think that's an open
question. I personally don't think it should be.

------
Sir_Cmpwn
Highly recommend this DEFCON talk:

[https://www.youtube.com/watch?v=HKQDSgBHPfY](https://www.youtube.com/watch?v=HKQDSgBHPfY)

------
at-fates-hands
I wonder if they're doing the same thing for the Zodiac killer and other high
profile cases.

------
scotty79
He spent 12 years of his life as rapist and murderer. I wonder why he stopped?
Mid-life crysis?

------
StavrosK
I don't see this anywhere: This is most likely not statistically significant.
A DNA match might be 99.99% accurate, but when you try to match based on a
database of a million people, you're going to get a few false positives. I
really hope the police have some more evidence to go on, because otherwise it
sounds like they just arrested an innocent person.

~~~
tysonzni
DNA wasn't the only evidence police had. 3 pieces of additional information:
1) his history in the Sacramento area, 2) he served in the Navy and law
enforcement which fitted the profile police were looking for, and 3) police
sketches matched a photo of his from the 70s.

edit: In addition to the physical evidence gathered from suspect's house that
could be linked to the crime scenes. This isn't public information yet.

~~~
jopsen
None of that makes him a suspect.

Lots of people in the DNA databases are relatives to someone who lived in
Sacramento.

I wonder how many close DNA matches did they find, and eliminate because there
was no viable relative who could be a suspect?

DNA is useful, but factoring up the probabilities in this case is not easy.
Good luck trying to explain that math to a jury.

~~~
tysonzni
_Lots of people in the DNA databases are relatives to someone who lived in
Sacramento._

The lead came from the police searching through DNA databases which identified
some set of relatives who were suspicious, but they later obtained the DNA
from the suspect himself which was an _exact_ match to what was gathered from
crime scenes.

------
iamgopal
I see a future where all foreign visitors needs to submit DNA instead of
finger prints.

------
randyrand
So 23andme shares our DNA with government? Screw that...

~~~
alexk307
No. Read the article or any other comment in this thread.

------
known
What if Evidence is planted by Corrupt officials?

------
btilly
Don't forget "innocent until proven guilty".

I want to know what DNA they got from the Golden State Killer, and how they
know that it was his. The guy that they arrested was a police officer during
the period where the killing was going on, in an era before DNA tests existed.
Did they take DNA from a sample that was accidentally contaminated by a police
officer at the scene, and conclude that the DNA belonged to said police
officer?

~~~
gwern
It sounds like they had semen or saliva from an old rape kit which has been in
storage for decades from a GSK rape victim
([http://www.nj.com/data/2018/04/how_a_nj_pathologist_may_have...](http://www.nj.com/data/2018/04/how_a_nj_pathologist_may_have_helped_solve_the_gol.html)),
they sequenced it, uploaded it to the genealogy website, got a hit on one of
his relatives, investigated that person's relatives until they noticed one guy
fit the GSK profile perfectly (law enforcement training, trouble with the law,
right age and height, lived in the right place) and then staked him out until
they got a discarded soda can or cigarette butt he tossed or which was in his
garbage can (remember, if you put your garbage can out on the street, anyone
is allowed to take it!), but the first sample was too degraded for a match and
they had to get a second one, which then matched perfectly.

~~~
tysonzni
Any guesses as to which genealogy website was used? All the services I'm aware
of (23andme, Ancestry.com) require that each customer provide their saliva
sample.

~~~
andrewem
Note that some services will allow you to upload a spreadsheet of SNPs which
you got from another testing service. If the police had access to a non-
commercial lab, say a state-run lab in California which can sequence a similar
set of SNPs, then they could upload the results to those sites. For instance,
FamilyTreeDNA allows raw data uploads, as does MyHeritage, and the non-
commercial site gedmatch.com.

Edit: or of course they could have sent a saliva sample to one of the
genealogy sites, assuming they had enough to part with some, and it was in
suitable condition to work with the site's test equipment.

~~~
gwern
> Edit: or of course they could have sent a saliva sample to one of the
> genealogy sites, assuming they had enough to part with some, and it was in
> suitable condition to work with the site's test equipment.

That's unlikely without special arrangements. Have you ever done a 23andMe
sample? The tube requires a _lot_ of saliva. My understanding it's vastly more
saliva than they need and the main reason is to make it impossible to
surreptitiously collect enough saliva to genotype someone without their
cooperation via 23andMe etc.

------
readhn
damn ... so the guy is going to jail based just on the data obtained from the
website?

What if the "match" is not correct?

This should scare a lot of people away from these family tree websites. One
day you might have FBI knocking on your door for being a close match to some
killer somewhere.

~~~
detaro
The article describes that they found him through the database, and obtained a
DNA sample from him to match to the evidence material.

------
devnonymous
Hang on, am I'm missing something - guy is a suspect, they have yet to find
proof he is the Killer and he has been arrested based on a second attempt of
trying to match the DNA after the first was inconclusive. Why does the article
read like they found the killer?

~~~
aqme28
The evidence sounds pretty damning to me. I'm curious why you think it's
wholly inconclusive

>Investigators then obtained what Anne Marie Schubert, the Sacramento district
attorney, called “abandoned” DNA samples from Mr. DeAngelo. “You leave your
DNA in a place that is a public domain,” she said.

>The test result confirmed the match to more than 10 murders in California.
Ms. Schubert’s office then obtained a second sample and came back with the
same positive result, matching the full DNA profile.

~~~
devnonymous
Ugh, my comment, alongwith a whole bunch of others, was moved by @dang from
this post

[https://news.ycombinator.com/item?id=16936533](https://news.ycombinator.com/item?id=16936533)

...which is a less detailed article.

