My (full, biological, non-twin) brother is a convicted felon, therefore he has had to submit a DNA sample to the federal crime database. I am not, and have not. If I were to commit a crime where I left behind DNA evidence, and that was analyzed, would it be close enough to my brother’s to flag him as a potential relation and therefore potentially connect me to the crime? Are there other circumstances where it could (i.e. parent, child, or fraternal/identical twin on file)?
I believe they can determine family members from DNA. It’s probably enough of a match to get you to submit your own sample
Apparently. They just solved the 40-year-old murder of one of the Righteous Brothers’ ex-wives using familial DNA.
Yep. They would absolutely be able to tell that the DNA belonged to a close male relative of your brother. Also, aren’t you familiar with DNA paternity tests, the staple of court shows and daytime talk shows? The closer the genetic relationship, the more similar your genes are going to be. Even if the DNA samples are abit stale.
Well that’s unfortunate. I wasn’t planning on committing any crimes anyway, but just knowing that I’ll never be able to pull off the perfect murder because my sibling messed it up for me is kind of upsetting.
Note, it’s not done in every state
Just salt the crime scene with your brother’s DNA. There has got to some forensic principle that favors a precise hit over a near-hit, right? The most astute thing they could say is “<brother> was definitely there. There are also samples that are…” and then either “close to <brother>, maybe a male relative”; “probably corrupted samples of <brother>'s DNA, so disregard”; or “don’t matter, we have a precise match. Arrest <brother>.”
Need to make sure that brother isn’t actually in prison at the time, and doesn’t have an airtight alibi. The usual T.V. procedural method is to leave brother a message telling him to meet someone at some weird out of the way or even nonexistent location, so he doesn’t have an alibi (but then there turns out to be a traffic camera he passes at a time that makes it clear that he couldn’t have gotten back fast enough to the commit the crime anyway).
Interesting you should ask.
They got the BTK Killer using his daughter’s DNA. From Wikipedia:
full sibling is going to be about 50% match to you. So is your father. So your uncles could be 25% match. it goes downhill quickly. First cousin, 12.5%.
Not the Y is a special case. All males get their Y chromosome pretty much intact from their father. (They’ve used it to show that Jefferson’s slave had children by him… or possibly his brother or his father or his uncle…) A statistical match indicates male from same paternal source.
To some extent, genes do change over time, so how much “drift” can indicate degrees of separation in historical timelines or further. (I.e. Native Americans split from remaining Siberians about 24,000 years ago.)
It’s certainly happened in the UK:
I thought of that conviction.
I saw the truck parked on the side of the M3 with a brick-shaped hole in the windshield the morning after as I drove to work, and was very pleased that the perpetrator was caught, many months later.
Not a criminal case but a mystery woman’s family was located via a DNA match with a cousin on 23andMe.
FtGKid2 did the 23andMe thing and found a match that’s ~3rd cousin. Later an uncle also had it done and of course it turned up FtGKid2. No surprise there.
There are several such commercial DNA databases now, as well as various police ones. Finding familial matches is getting more and more likely.
If you are not guilty of something, you could still end up in serious trouble. If the police find someone in your family is a close-ish match to the DNA of a perp, they might decide you’re the closest in appearance to the suspect, etc. You get arrested, charged, etc. Eventually cleared via the DNA not being an exact match but by then you’ve burned through thousands of dollars in legal fees, lost your job, turned into a pariah within your community, etc.
But, but—they use it on Law & Order: SVU every other week! :eek:
The Y-chromosome is turning out to be very interesting in terms of tracing distant relatives because of how slowly it mutates and the fact that it does not (normally, at least) recombine.
Here’s a case where the DNA of a wanted murderer in Washington State (1991 murder) has been paternally linked via the Y-chromosome to an early (1600’s) settler family in Massachusetts. Police now believe that the killer (whose exact identity is still unknown) is likely to have the last name Fuller.
Henry Louis Gates, Jr., the African-American man who was famously arrested for burglary for trying to break into his own home, has Y-chromosome type R-M222, which is associated with Irish and Scottish Gaelic ancestry. I also have this type, so this is a particular area of interest for me.
If you get a massive blood transfusion just before they test your blood, will that mess up the DNA test?
I vaguely recall seeing a sci-fi show where the perpetrators of a crime set off a “DNA bomb” to confuse any attempt at identifying them. I always wondered if that would work.
If I decide to lead a life of crime my first order of business will be to raid the dumpsters of barbershops and mani/pedi stores!
Now that is a hell of a good question!
Me? I am screwed sort of. AB negative blood type, so as a fairly small % of adult females in the US share my blood type, even if all they can do is blood type without getting enough DNA I am enough at risk of being pined for a crime.
I would have hated to have luminol’d my old house, we had a pair of dogs get into a fight in the living room, we were still finding random little visible blood spatters for almost 15 years [until it burnt down…]
Though I really have to be peeved at the idiots who did a Lizzie Bordon documentary about 10 years ago. They luminol’d the area in the basement near the jakes [primitive toilet facility] and found washed out blood patches. ALl I could think of was 'a predominately female house population in an era with hand laundering everything, sharing a primitive toilet facility in an era when you used rags that needed to be hand washed out to deal with menstrual fluids … no shit you would find dilluted blood splashed around. Ever hand washed using a scrub board and hand wrung and hung up laundry before? Done a pitcher and pan ‘shower’ with menstrual fluid on your thighs? Hells bells, I have cleaned ‘blood drops’ off the bathroom walls and floors at home, and I know I tried to be neat and tidy about things [I admit there was a bit of a learning curve in dealign with a diva cup…oops:o] If there is a menstruating woman there will be blood evidence.
Thought this latest DNA identification story was worth a bump: a set of 14 1,200ish year old skeletons are DNA tested, found to all be from the same mitochondrial lineage, and that one pair was a mother and daughter and another were a grandmother and grandson.