How Can The Police Find You By Your Dna....

[trt]

if you have never been in trouble or charged with any crime?

[Jackdaw33]

By contacting the relatives of a suspect and asking for a sample.

[Togo]

If you have a relative who is identified as having committed a crime and their DNA is in the "bank" a random sample can be matched to that profile and bingo.

[Buenchico]

You wouldn't need to have been charged with a crime. Simply being arrested (even if later found to be completely innocent) allows the police to take a DNA sample, which they can then retain.

Or, as JD33 says, a close relative might produce a 'near match' DNA sample, which would draw the attention of the police to his/her family members:
http://news.bbc.co.uk/1/hi/england/hampshire/8574529.stm

[Buenchico]

It's worth remembering that over a third of British men acquire a criminal record before their 30th birthday, so the chances of being related to someone who's on the DNA database are remarkably high!

[trt]

So how did they match the DNA of the bloke, (think Belgium) who was arrested and found guilty of the case of 25-year-old Joanna Yeates, who was found strangled to death and partially covered in snow on a county lane on Christmas morning 2010. The discovery of her body ended an eight-day police search, but the authorities and the media focused on Joanna's landlord and neighbour, Christopher Jeffries, while the real killer was on the loose.

This was on today's TV, with Judge Ryder the barrister considering the case.

[Zacs-Master]

http://www.lgcgroup.com/about-us/media-room/latest-news/2011/lgc-forensics-provides-key-evidence-in-jo-yeates-i/#.V2sFldR4WrU

http://www.crimeandinvestigation.co.uk/crime-files/joanna-yeates/trial

[trt]

Thanks Zac,

I had read your first link, but not the second, which gave me my answer.

[Zacs-Master]

:-)

[EDDIE51]

As Buenchico has said every one who has ever been arrested even if released without charge has their DNA taken and stored. The police now have a DNA record of a large % of the population. It can also identify if someone is related to a stored DNA profile. So if your brother, sister, father, mother, son, daughter, grand child, grand parent has been arrested they have a good match to you. Enough for them to make detailed investigations.
The police want every ones DNA to be taken at birth and stored. They have been refused that so far but they will keep trying.

[THECORBYLOON]

The programme did show a reconstruction of the man being interviewed in The Netherlands and he was asked to consent for a mouth swab to be given which he did and that was how they obtained the DNA.

[Jackdaw33]

Although long pre-dating DNA, the case of R v Griffiths (1948) makes interesting reading. The police decided to embark on the monumental task of fingerprinting every man in the town. They caught him.

[Peter Pedant]

Think fambly tree

as a result of darwin and Mendel and ALL THAT, you will share half your genes with each parent - so if they have another child ( that would be your brother and sister, they will have half in common and therefore by simple multiplication a quarter with you) and a nephew or niece will share an eighth

This is a partial match - and if you test for enough variable genes, will be picked up

[Peter Pedant]

// Although long pre-dating DNA, the case of R v Griffiths (1948)//

In a plymouth case where a disabled man used to pretend he was a decorated ex military man - he ended up dead having been stamped upon ( a marine thing apparently ) so they took 17 000 statements and the two that didnt agree were the two what had done it

hailed as a triumph for standard police practice

[Peter Pedant]

dammit all
as I wrote I wondered about the mothers contribution and some of the figures are doubled ....

https://customercare.23andme.com/hc/en-us/articles/202907170-Average-percent-DNA-shared-between-relatives

[Barmaid]

I seem to recall that the police can take DNA on an arrest if the detainee consents or if the Inspector authorises it. In many less serious offences, the detainee will refuse a sample although it is usually authorised on charge. I think such authorisation is only usually given for serious offences before charge. If the person is acquitted, the samples should be destroyed. I cant remember how it all works now, but it is all set out in PACE 1984. Hopefully New Judge will explain.