Rekna

On 60 minutes tonight there was a story about DNA being used to solve crimes. They say that the odds of DNA matching someone other then the source is 1 in 6 billion (basically a statistical impossibility).

The story got me thinking about this. Police already keep a network of fingerprints. If you get arrested your fingerprints go into a database and all police everywhere now know your fingerprint. The question I have is do you think we should do the same thing with DNA? If you get arrested when they take your fingerprints they also take your DNA. Or maybe even take it at birth. Do you think this would be to invasive?

Personally I think this would not be to invasive and would help not only deture crime but get criminals off the street. The key is the police need to keep the DNA absolutly private. Companies should not have access to them (we don't want DNA descrimination to occur). Also it would be very bad if cloning scientists started getting hold of peoples DNA.

What do you think?

(ps. Hey look this post isn't about bush or kerry!!!!!! let's keep it that way)

Dwayne

OK no matter who is in power, the thought of my DNA on catalog makes my hairs stand on end. DNA is basically the ultimate ID, But since its so easy to steal DNA from someone that scares the bageezus out of me. Basically if everyones DNA was on record, all someone would have to do is take some hair or saliva of some one and plant it at a crime they commited and boom! Your a suspect.

Rekna

I really don't think that would be a huge issue. First there will typically be more than just a small piece of DNA as evidence at a crime scene. For instance if you rape someone your semen will be inside her. If there is blood on the ground... ect. Planting fingerprints isn't exactly difficult and there hasn't been a lot of problems with that. At least with DNA there is a large chance that the planter would also leave behind some evidence. People have nothing to hide when it comes to DNA.

I think the government could implement a very secure method of handling it and authenticating it also. Something along the lines of they submit their DNA codes to a checker that then replies with whose DNA it is. No one except for a few people have access to what codes person X has until a match is made. (This would make synthetic framing highly improbable).

Also i'm sure that if this were the case the courts would put limits on what kind of DNA evidence is admissible. The big thing is it could be used to solve crimes in which there is ample DNA evidence.

There are really 2 types of people who don't want to give DNA, those that have done something wrong and those who are planning on doing something wrong.

The_Dunedan

And what about those of us who are not criminals and object to being treated like them? Oh, right, I'm sorry, I thought this was a free country...silly me. I keep forgetting that, to a Statist, everyone either IS a criminal or WILL BE a criminal at some future time. I will -not- be "typed" like some rapist; I will not be treated like a criminal when I have done nothing wrong.
To paraphrase King Leonidas Of Sparta: Come and get it!

Rekna

If your not a criminal why do you care? If someone killed your kids and left DNA evidence would you want that evidence to be able to find the killer or not?

You have to give your fingerprint to cash a check at a lot of banks do you complain about that?

The_Dunedan

Yup. The last time someone tried to make me give a fingerprint, I withdrew my money, closed my account, and walked out. In the course of all this, I let the teller, the manager, AND the security-gaurd know exactly why I was doing so.
I cash my checks at a bank that doesn't require such nonsense. And I make sure to thank them for not requiring it.

As for DNA and someone killing my kids: Fine. Lift the DNA from the crime-scene, cross-match it with the blood OF A SUSPECT. But don't expect me to provide a DNA sample for some general, nationwide database when I havn't done anything.

As for why I object: I am not a criminal. I have done nothing wrong. Therefore, I object to being treated like a criminal; I find it demeaning, insulting, and rediculous: not to mention your idea's flagrant unConstitutionality. I will not stand for such treatment, and anyone who tries to force it upon me will have a fight on his hands.

Rekna

What if it was a completly random killing, say a serial killer. They had no leads. Not to mention he has killed 15 other little girls. Are you still glad they don't have everyones DNA on file?

I don't think the government having a list of our DNA hurts us at all. Hell they could even make a system where the DNA is stored so no person whatsoever knows the DNA and cannot know the DNA (simalar to the way shadow passwords are done in unix, even the admin doesn't know the passwords). It could all be done on computer.

I think the benifits far outweigh any "privicy" rights you think it violates.

smooth

Fingerprinting is not a panacea, and neither is DNA.

Two of my professors study exactly how the processes are fallable, yet hidden by our intrigue with technological advancement.


First of all, evidence is studied after a suspect is in mind. While this may seem logical, it opens the door for a few problematics:

DNA and fingerprinting ultimately relies upon human corroberation. While computers initially run the scan, experts ultimately decide on what matches and what doesn't. So far, states vary on what the minimum requirements for a "match" are before being evidence of one of those astronomical anomalies of snagging the wrong person.

If you look at an ink blot, do you think the process would be more reliable if you were asked: "Do you see a butterfly in there" or "What do you see" (and the person replies: butterfly"

That is, you have a suspect. You think in your mind the person committed the crime. Detective lays the crime scene DNA slide next to the suspect's slide and matches it. Things that don't match are "noise" and things that don't quite match are likely's. After some agreed upon number of matches are reached (differs by state, remember, and municipalities before it even goes to the DA for indictment), the noise is tossed (explained away) and the likely's "become" apparent or are scrubbed.

I hope this isn't starting to look too inconceivable that someone could be inadvertantly processed for a crime not committed by him or her. Add to this equation the idea that once a match is found, the police don't scrub the scene for more suspects--and they don't keep finding more people in the pool of 'applicants' either. I suggest (and evidence corroberates this) that the amount of time and care that goes into a case will vary indirectly porportionate to the class level of the victim (usually low class, btw--doesn't quite hold so strongly when an upper class citizen is harmed, which is actually very rare and even more rare by someone outside of one's class level) and the suspect.

This is one of the most pressing issues with both techno-identification processes. I don't enter into this equation the question of contamination (which is very real--at least one person was released just recently due to lab conditions in Texas, my prof was the guy who busted the case's asshole open when the lab techs were found to be doing all kinds of shit and the lab was leaking chems all over the place and etc).

But the problems I identified more closely are very persuasive because they can be dealt with and they lay no blame on the officers--they result from normal psychological prompting processes which researchers and academics (and detectives, btw, in their interview techniques) know and document copiously.

The single best way to address this that I can think of is to have one person identify what he or she thinks are points of match and have an independent observer identify points of match. Then you allow the two DNA strips to be brought together and a special statistic (the name of which escapes me right now, but it might be a Chi--hopefully another stats member can bring in the stat that is used to verify validity between more than one qualitative observer) is run to determine how statistically close they were to one another.

But that's not done. And until it is, DNA testing and claims about it should be viewed with skepticism. And all this is true for fingerprinting, as well.

__________________
"The theory of a free press is that truth will emerge from free discussion, not that it will be presented perfectly and instantly in any one account." -- Walter Lippmann

"You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists." -- Abbie Hoffman

The_Dunedan

Rekna:
I don't think you understood me. I don't -care- what you think or feel about this issue. I don't care how many Statists feel that way. And neither do a whole helluva lot more people. They will all have the same response I will if someone tries to forcibly "type" them: they ( and I ) will kill whoever is trying to do this to them.
It's that pesky 4th Amendment, dontcha know.

Rekna

smooth you were hitting on the same idea I was for matching. In my case instead of using people I use a computer. But this way the person doing the testing can't fudge his results because he doesn't know what his target is. I believe the stats test you are looking for is a goodness of fit test also known as the chi squared test.

Dunedan so you won't under any circumstances support creating a database with all people. How about we discuss one of my other idea's mentioned. All people who are arrested get tested. That is anyone who is taken in, gets their mugshots, and fingerprints done. In that case it should be perfectly legal to do because you are a criminal. Reguardless if it is something minor like disorderly conduct or drunk in public.

This would at least help eliminate a lot of the usual suspects.

hokieian

At first thought DNA cataloging sounds like a great idea - a foolproof way of identifying a suspect in a crime. And I think in reality it would be a great tool for law enforcement to have.

I think the main issue involved is one of money, as is the case with most things. Fingerprints are cheap. The equipment to capture one costs pennies and all you need is a scanner and some basic software in order to put it into a computer database.

DNA, on the other hand is very technical and time consuming, not to mention extremely expensive. The reagents, equipment, training, space, and technical staff required to create such a database would result in a substantial expense. Many of the cities and counties and states in the US have no extra money to pay for this. Not to mention the amount of time it would take to catalogue each person's DNA profile. There is already a tremendous backlogue of suspect DNA waiting to be tested and matched to crime scenes.

hokieian

On the other issue, about whether or not people would feel comfortable with the government having their DNA profile in case it got into the hands of insurance companies, etc. I don't think I would have much of a problem with this, namely for the fact that for crime purposes, they do not sequence a suspects DNA.

Basically, there are proteins called restriction enzymes that cut DNA at specific sites (for example, the restriction enzyme BamHI cuts DNA at the sequence GGATCC whereas SmaI cuts DNA at the sequence CCCGGG). Becasue each persons DNA sequence is not identical, these restriction enzymes will cut each person't DNA at different sites, and by looking at the size of the fragments that get cut, you can match the DNA to a specific person (because the size of no two people's DNA fragments after cutting will be identical).

To get to the point, if the police/government were required to destroy your DNA after they acquired your restriction profile, I would have no problem with them keeping a catalogue of people's DNA. However, if they banked the DNA and were able to sequence it later on to look for specific genes that may or may not be present and then share this information with others, I would most likely be opposed to the idea.

With the ability to sequence DNA growing easier every day, this is a debate that will not go away anytime soon.

The_Dunedan

See, I was under the impression that one was "innocent until proven guilty beyond a reasonable doubt" in this country. My mistake.
I'm not a criminal until I'm convicted; sorry. Once a person's convicted, sure, take their DNA, especially if we're dealing with a violent criminal. That person surrendered their rights when they initiated the use of Force or Fraud. But until conviction, leave them alone.

hokieian

I wouldn't disagree with that. I don't think the government (or whoever) should force anybody to give up a sample of their DNA unless that person is a suspect in a criminal case.

If you want to voluntarily give them DNA (or your child's DNA to aid in finding/identifying the kid in the case of kidnapping), by all means go for it.

Basically, I think DNA evidence/samples should be treated very similarly to fingerprints.

Rekna

So are you saying cops should only be able to take fingerprints of people who have been convicted of a crime and not just arrested for it?

Hell for all I care i wouldn't mind if people were forced to give fingerprints/dna if they had traffic violations. Afterall they still commited a crime.

adysav

One of the arguments I heard against DNA cataloguing was that personal information can be obtained from it. In the future it is likely we will be able to determine a persons medical conditions and predisposition to medical conditions simply from looking at their DNA. As far as I'm aware the police do not have (and should not have) access to a persons medical information under normal conditions.

As for the 'whats the problem if youve done nothing wrong' argument, the simple answer is that we should have a right to privacy. If you had cameras pointed at your house and there was a policeman on every street corner to whom you were obliged to disclose where you were going and what you were doing, it might seem a little different, but still those who have done nothing wrong have nothing to fear... right?

Rekna

This is why we use a protected system that does not grant access to DNA it only does checks to see if they are the same. The machine it's self doesn't even store a persons DNA just simply a hash of the DNA. This way it would be only usable for identification and nothing else.

adysav

How can you create a system that noone has access to? Are you going to train a team of tech ferrets to do maintenance work?

Rekna

No it is called hashing.

Warning math incomming

We have a function F(x) where x is the DNA sequence.

F(x) is easy to calculate but F-1(x) is almost impossible or impossible to calculate. F is now the hash function. Also F(x) is unique for all x. So what you do is instead of storing x you store F(x). Then when someone submits a DNA sequence you hash it using F and compare it's F(x) to all the other F(x)s you have stored.

If you want more information look up passwords in unix (and I think windows does this also).

adysav

I get what you were on about but you misunderstand me. How can you physically run a system that no human being has access to? Someone has to put the data in there in the first place and so someone has access to it.

I know how passwords work in Unix, and since you do too you will know that they are not completely secure.

Rekna

UNIX passwords are insecure because they are short. In this case the DNA sequence is how long? Brute force breaking it wouldn't make it insecure.

Now as for people entering the information, yes it is insecure in that sense but so is purchasing things online. Or using your credit card at a supermarket. The potential dammage that a person entering the infomation could do is very minimal. They would get a very small number of peoples DNA and then what would they do with it? Plus that would be highly illegal.

adysav

They use just enough to make sure that they won't often get false matches.
Well, so that it's 1 in a billion anyway. That still means there's a likelihood that 6 people will match the profile as there are about 6 billion people. A 7 character password of all lowercase letters has more than 8 billion different combinations.

Obviously it's not a simple matter of brute forcing someones DNA, whatever that might involve, but yes it would need to be encrypted to stop prying eyes.
The worrying thing is that the powers that be are considering storing physical DNA samples from each person.