DNA
Date: 22 August 2010 07:00
Producer: Eugene Botha
Presenter: Chantal Rutter
Show: Carte Blanche
To watch the show on-line click here for part one and click here for part two of the story.
1979: A grim scene in a Los Angeles suburb. An elderly woman is found dead on the floor of her kitchen. There’s evidence that she was also sexually assaulted.
David Doan (Deputy Chief: LAPD): ‘There were a number of leads on that case. There was even a possible suspect – a neighbour – but there was not enough evidence to establish that he committed the crime.’
But the case went cold, says David Doan, Deputy Chief of the Los Angeles Police Department.
David: ‘What we refer to as ‘cold cases’ means a case where the trail has gone cold on leads… there are no further leads.’
All the evidence, including clothing stained with semen, was put into storage. But the case was not forgotten.
David: ‘Here in the Los Angeles Police Department we never close our homicide cases, we always consider them open.’
In 2003, 18 years after the murder, DNA profiling had become a useful tool in solving crimes.
Cold case detectives re-investigated the case. They sent the victim’s clothing for analysis and obtained a DNA profile of the murderer.
This unknown profile was then entered into their DNA database system, known as CODIS.
David: ‘In 2009 an individual was stopped for driving a stolen vehicle. His DNA was taken and we received what we refer to as a ‘cold case match’. He happened to be 17 years old at the time when he committed the crime and he was 51 years old when we identified him as the suspect in the case – another example of an individual who would not have been held accountable for the murder of this elderly woman if it had not been for a DNA database.’
And, all over the world, DNA profiling and DNA databases have become major tools in crime fighting.
David: ‘I cannot imagine doing police work today without DNA no more than I would be comfortable today seeing police work without fingerprints and photographs.’
One would think that using DNA in this way would be standard practice wherever profiling is available. But it’s not.
The LA murderer would never have been caught in South Africa, and not because of backlogs.
There’s another reason.
Vanessa Lynch (Director: DNA Project): ‘Where we fall short is that we’re not progressing with our legislation as we should.’
Vanessa Lynch is Director of the DNA Project, and promotes the use of a DNA as a crime fighting tool. She says the SAPS’s DNA profiling capabilities are excellent.
Vanessa: ‘The quality of the processing, the DNA analysis that is coming out of our laboratories, is in fact superior.’
Although we’ve often reported on the massive backlogs in processing forensic evidence by both the police and the Health Department, the DNA profiling unit at the Police Science Laboratory is apparently world-class and delays are minimal.
Vanessa says the problem is that current legislation is outdated and prevents the full use of DNA to solve crimes. New forensic legislation has already been sitting before a parliamentary committee for more than two years.
Vanessa: ‘But what they did was they split it between fingerprints and DNA. Initially it dealt with both. The committee has just passed Phase 1 of the bill, which is fingerprint, and now it has been passed through the national assembly and various areas of parliament. They will then look at Phase 2. They have decided, however, that they want to go on an overseas tour to both the UK and Canada to look at how other systems operate.’
While our legislators are battling, other countries have addressed many of the problems pertaining to forensic DNA profiling.
To understand the issues involved, one first has to understand what forensic DNA profiling entails.
Colonel Luhein Frazenburg of the SAPS’s Forensic Science Laboratory in Pretoria explains.
Col Luhein Frazenburg (Commanders: DNA Case Work): ‘Basically what we do here is we do all DNA analysis for all DNA cases in South Africa. Blood samples, semen samples, saliva, any human tissue is tested here.’
Chantal Rutter (Carte Blanche presenter): ‘Colonel, what is DNA?’
Col Frazenburg: ‘DNA stands for Deoxyribonucleic Acid. It is a molecule that’s present in all living cells. It’s the genetic blueprint of a person. Now basically half of your DNA you get from your mother and half of your DNA you get from your father. Also, your DNA does not differ over your lifespan and all your DNA is the same whether you look at your hair samples, your blood samples, bone, or tissue samples.’
Luhein showed us around the state-of-the-art forensic science laboratory.
Chantal: ‘This is something really special. It’s one-of-a-kind and it is right here at the police forensic laboratory in Pretoria.’
It’s the only fully automated DNA profiling system in the world and was developed right here in South Africa. It can process 800 samples a week. And it’s in part thanks to this machine that there are no DNA profiling backlogs in Pretoria and only a few in the Cape.
DNA profiling entails extracting and analysing a DNA strand from a human cell.
Vanessa: ‘95% of your DNA, they in fact don’t know what it codes for. About 5% of your DNA they know you have blue eyes or two legs… two arms, etc. But the 95% which they call ‘junk DNA’ or ‘non-coded DNA’ in fact doesn’t code for anything that they understand.’
There are millions of these pieces of non-specific DNA.
Vanessa: ‘They only take nine numbers out of those millions of markers of your non-coded DNA and that’s all they need to identify you as an individual.’
Each of these nine selected areas on the DNA strand contains contributions by one’s parents. They can be expressed by a pair of numbers. So, in effect, your forensic DNA profile consists of a list of nine pairs of numbers.
The chance of two people having the same numbers in the nine pairs is one in 79 trillion. In the US, they use 13 pairs of numbers for a forensic profile.
Vanessa says that the lack of proper DNA legislation in South Africa prevents the police from fully utilising this invaluable identification tool to solve crimes.
For example, current laws don’t allow for DNA evidence obtained at all crime scenes to be processed.
Vanessa: ‘If you collect DNA evidence from a crime scene, but you don’t have suspect, they won’t process that DNA profile.’
Furthermore, our outdated legislation prevents the police and other law enforcement officers from taking DNA samples from suspects.
Vanessa: ‘A DNA sample currently is taken by way of a syringe by a medical practitioner. This is by virtue of an old 1977 act which was promulgated long before the advent of DNA profiling.’
And, under current legislation, the right of an individual to privacy is perhaps the main issue. Taking a DNA sample and preserving it on a database is seen as an invasion of privacy.
So unless DNA was involved in convicting them, the DNA profiles aren’t taken from convicted murderers, or rapists already serving time. Vanessa thinks privacy fears are unfounded.
Vanessa: ‘Even if somebody, for instance, got hold of the DNA database and looked at those sequence of numbers, there is nothing they can do with them. They cannot read any genetic disposition, whether physical or medical, from those sequence of numbers. And that is why throughout the world it has never been challenged constitutionally. It does not represent an invasion of privacy and we need to understand this in South Africa.’
So maybe another overseas trip for parliamentarians is not such a bad idea after all.
Vanessa: ‘Perhaps they’ll realise when going there, not only that it is successful in terms of crime resolution, crime investigation, and ultimately crime prevention, but also that all the issues that they are concerned about have legitimately been addressed by virtue of legislation that has been passed that shows that it is not an invasion of rights and that it is okay for a police officer to take a swab from you in order to take a DNA sample.’
David: ‘I think we need to find a compromise between a right to privacy and an ability for law enforcement to find people who have committed some pretty heinous crimes. And I think the method that we’re using currently gives you that balance.’
And if these issues can be resolved, our tiny DNA database of 123 000 profiles could be significantly expanded. It could then be used for cross-referencing like databases elsewhere in the world.
Chantal: ‘So, in what way do you think legislation should be changed?’
Col Frazenburg: ‘Well, it would be advisable to have as many as possible of arrestees on the database so that you can compare that to the crime samples that we get it.’
In parts of the world where national DNA databases have been implemented, crime solving has skyrocketed. And there’s another benefit.
Vanessa: ‘It becomes such a strong form of evidence that when a suspect is presented with a positive DNA match that links them to the crime they plead guilty. In the UK, 82% of suspects that are presented with this type of evidence, plead guilty – 82%! You can imagine what that does to your criminal justice administration.’
Deputy Chief Doan says those cases solved with DNA profiles did not violate anyone’s rights.
David: ‘We don’t think these people’s privacy, the suspects’ privacies, were violated because I don’t know anything about their genetic history. I simply know what their DNA looks like in 13 places.’
But until we have new DNA legislation in place, criminals will continue to get away with murder in this country.
Vanessa: ‘I think it needs to be urgently addressed because I think two years is already too long to have waited to pass this urgently required legislation.’
