Bacteria may help police identify suspects

Police forces may soon be able to add another forensic tool to their armoury following a study showing that it is possible to identify a person from the bacteria they leave behind after touching an inanimate object such as a computer keyboard or telephone.

Fingerprints can provide an exact match between an object and someone who touches it but the new technique exploits the fact that the microbial community living on someone’s hands is sufficiently unique to a person for it to be used as another form of forensic identification.

Scientists said that with further development it might soon be possible for the police to take a swab from a piece of equipment and be able to decide who was using it days or even weeks ago, even if they are unable to recover any fingerprints.

A preliminary trial has shown that the new technique is between 70 and 90 per cent accurate in identifying someone who used a computer mouse from 270 samples of hand swabs collected at random. Scientists said that the accuracy could be improved with further research.

“Each one of us leaves a unique trail of bugs behind as we travel through our daily lives. While this project is still in its preliminary stages, we think the technique could eventually become a valuable new item in the toolbox of forensic scientists,” said Professor Noah Fierer of the University of Colorado at Boulder, who led the study published in the journal Proceedings of the National Academy of Sciences.

Previous work carried out in 2008 established that the combination of bacteria carried around on someone’s hands – typically about 150 species – is pretty unique to them and it not affected by handwashing. It identified more than 4,700 species of different bacterial species in total across the 102 hands but only five species were shared by all 51 participants and only 13 per cent of the bacterial species found on a single hand were shared by any two people.

“The obvious question then was whether we could identify objects that have been touched by particular individuals,” Professor Fierer said.

In the latest study, the scientists swabbed individual keys on the keyboards of three personal computers and were able to match them in terms of their mix of species to the bacteria living on the fingertips of each computer’s owner.

In another test, the scientists were able to match nine computer mice that had not been touch for 12 hours to their owners from a randomly-selected lineup 270 people who had never touched the mice and whose palms had been swabbed and analysed for their bacterial flora.

In all nine cases the bacterial community found on each mouse was much more similar to those found on the owner’s hand, the scientists said. Further tests showed that the bacterial community found on a computer mouse remained essentially unchanged after two weeks kept at room temperature.

“That finding was a real surprise to us. We didn’t know just how hearty these creatures were,” Professor Fierer said.

The technique relies on a revolutionary way of analysing an entire collection of genomes in one go, called “metagenomics”. At present it is possible to sequence bacterial DNA from 450 samples at once but this number is expected to go up to 1,000 by next year, Professor Fierer said.

PROMOTED VIDEO
Life and Style
food + drink
Arts and Entertainment
musicBand's first new record for 20 years has some tough acts to follow
Life and Style
Shoppers in Covent Garden, London, celebrate after they were the first to buy the iPhone 6, released yesterday
tech
News
Liam Payne has attacked the media for reporting his tweet of support to Willie Robertson and the subsequent backlash from fans
peopleBut One Direction star insists he is not homophobic
Life and Style
healthFor Pure-O OCD sufferers this is a reality they live in
Arts and Entertainment
A bit rich: Maggie Smith in Downton Abbey
tvSeries 5 opening episode attracts lowest ratings since drama began
News
ebooksAn unforgettable anthology of contemporary reportage
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Website Editor

£15 - £17 Per Hour: Clearwater People Solutions Ltd: Our client is currently r...

Primary Teachers needed for supply in Ipswich

£21552 - £31588 per annum: Randstad Education Cambridge: We are looking to rec...

Primary Supply teaching jobs in Stowmarket

£21552 - £31588 per annum: Randstad Education Cambridge: Randstad Education ar...

Year 1 Teacher

Negotiable: Randstad Education Birmingham: The Job An inner city Birmingham sc...

Day In a Page

A roller-coaster tale from the 'voice of a generation'

Not That Kind of Girl:

A roller-coaster tale from 'voice of a generation' Lena Dunham
London is not bedlam or a cradle of vice. In fact it, as much as anywhere, deserves independence

London is not bedlam or a cradle of vice

In fact it, as much as anywhere, deserves independence
Vivienne Westwood 'didn’t want' relationship with Malcolm McLaren

Vivienne Westwood 'didn’t want' relationship with McLaren

Designer 'felt pressured' into going out with Sex Pistols manager
Jourdan Dunn: Model mother

Model mother

Jordan Dunn became one of the best-paid models in the world
Apple still coolest brand – despite U2 PR disaster

Apple still the coolest brand

Despite PR disaster of free U2 album
Scottish referendum: The Yes vote was the love that dared speak its name, but it was not to be

Despite the result, this is the end of the status quo

Boyd Tonkin on the fall-out from the Scottish referendum
Manolo Blahnik: The high priest of heels talks flats, Englishness, and why he loves Mary Beard

Manolo Blahnik: Flats, Englishness, and Mary Beard

The shoe designer who has been dubbed 'the patron saint of the stiletto'
The Beatles biographer reveals exclusive original manuscripts of some of the best pop songs ever written

Scrambled eggs and LSD

Behind The Beatles' lyrics - thanks to Hunter Davis's original manuscript copies
'Normcore' fashion: Blending in is the new standing out in latest catwalk non-trend

'Normcore': Blending in is the new standing out

Just when fashion was in grave danger of running out of trends, it only went and invented the non-trend. Rebecca Gonsalves investigates
Dance’s new leading ladies fight back: How female vocalists are now writing their own hits

New leading ladies of dance fight back

How female vocalists are now writing their own hits
Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments