Australian federal police are using next- generation DNA technology to predict the appearance of potential suspects.
The technology can predict a person's appearance based on their DNA left at a crime scene, even if there is no matching profiles in police databases.
According to the Agence France-Presse,MPS can predict gender, biogeographical ancestry, eye colour and hair colour in the coming months.
The technology is a game-changer for forensic science, but also raises issues around racial profiling, heightened surveillance and genetic privacy.
How does it work?
The basis of our genetic code is formed by two interlocked chains. Each strand of DNA has four units that repeat in patterns. The human genome contains 3 billion pairs of bases.
The 0.1% of the genome that makes each of us genetically unique is what forensic analysis is interested in.
Traditional DNA profiling focuses on 24 sites on the genome where different lengths of bases are found in different people. The site sequence does not contain any specific genes that determine physical characteristics. One of the 24 target sites is on the X chromosomes and the other is on the Y.
Prof Adrian Linacre, chair in forensic DNA technology at Flinders University, said that if he told you his profile, it wouldn't mean anything. You couldn't see that and think that he's from northern Europe.
A person's genetic fingerprints can be given by the different sequence lengths at each of the 24 sites. Criminal databases can be used to match crime scene DNA with criminal profiles. Linacre said that links could be made to relatives if the person was not on the database.
What is massive parallel?
MPS has been used in forensic cases overseas for more than a decade.
Linacre describes it as a huge change. He said that the technology is capable of doing tens of millions of bits of DNA in one go. The new methodology is telling you things about the person.
Rather than looking at the length of the strings, theMPS can look at the single nucleotides.
There are several base changes that affect eye colour. Linacre said that you have a high chance of saying that the guy has bluey-green eyes.
California police used genetic genealogy tests to catch Joseph James DeAngelo, the Golden State Killer, but they did not use the same method to identify people's ethnic origin.
How will the next-gen DNA sequencing be used in Australia?
The new technology will allow investigators to get more information about a potential suspect even if there is no match on a law enforcement database.
The technique could be used in missing persons and unidentified human remains cases.
Linacre said that most things they find at crime scenes are combinations of two or three people's genes. Traditional DNA profiling techniques work well on degraded DNA, but using a mixture of fragmented DNA could lead to incomplete results. We haven't developed good software programmes to deconvolute massive parallel data.
Are there ethical concerns?
Dr Paul Roffey, the leadMPS scientist at the agency, said in a statement that the agency planned to widen prediction capabilities to include age, body mass index and height.
Fine detail predictions for facial metrics such as distance between the eyes, eye, nose and ear shape, lip fullness, and cheek structure are what we will be seeking.
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Genetics can be used to determine age, as well as body composition and height, which are influenced by environmental factors.
The ability to predict the phenotype of a suspect raises ethical issues, particularly around racial profiling, said Dr. Howes.
She said that being able to determine a suspect's ancestry could place a whole population group under suspicion. There might be lots of people who fit that description.
Privacy of genetic information is a concern. Linacre said that there is a line which needs to be drawn if you start to look at other parts of DNA which are very personal to you.
The introduction of any of these things is a problem because the community is not fully aware of what could be involved. Function creep is when a scientific technique is introduced for one reason and gradually becomes used for other purposes that weren't agreed to initially.
There should be clear thresholds in place when this can be used.
