Showing posts with label DNA. Show all posts
Showing posts with label DNA. Show all posts

Friday, August 26, 2011

The Australian: Forensic science in the dock

Hantu Laut

Forensic science and DNA analysis are not yet a perfect science, there are many grey areas and many of the so called experts in Australia are not truly competent to give foolproof analysis of DNA samples let alone our Malaysian expert who had been criticised by the foreign experts.A mistake or carelessness would have sent an innocent man to prison or worse the gallows.

With the ongoing Anwar's sodomy trail the debate on DNA and forensic science is heating up in court with foreign and local experts and solicitors from both sides slugging out in the court room.

Below is a report which incidentally mentioned one of the Australian experts in the Anwar's sodomy trail, the well known and hypercritical Dr Brian McDonald.

Forensic science in the dock

The Australian

BRIAN McDonald knows he has few admirers among the forensic scientists at the nation's DNA testing laboratories. "I am the antichrist as far as forensic science is concerned," he says.

The reason is simple. McDonald, an independent DNA consultant and molecular geneticist, has built a career by finding flaws in the test results some of these laboratories have provided for the justice system.

Of the hundreds of tests for DNA (basic genetic cell material) that have been referred to him by defence lawyers, he says, he has found problems in 30 per cent to 50 per cent of them.

Such a high rate of contested test results is one reason there is growing unease among lawyers that, in some cases, DNA evidence alone is sending people to prison.

DNA analysis, when applied correctly, is widely considered the most reliable form of forensic science. But if the problems picked up by McDonald have also been present in even a small proportion of other DNA tests used in court, there is a risk some people in jail are victims of scientific error.

The growing doubts about the evidence of scientific experts is not confined to DNA analysis.

A debate is raging in academic circles about what some lawyers believe is a lax approach by the courts that is exposing juries to "junk science", opinions presented by so-called experts who are unable to explain the scientific methods that helped them reach their conclusions.

Courts in Queensland and the Northern Territory have drawn the line at accepting evidence from people who claim to be experts in forensic odontology, or matching bite marks.

But a recent article in the Criminal Law Journal has unleashed a barrage of criticism at far more established fields of forensic science as well as new areas such as barefoot morphology, or the identification of people from the weight-bearing patterns left by their feet. The authors of that article, who include David Field, director of Bond University's Centre for Forensic Excellence, call for a new approach from the courts to weed out unreliable forensic evidence.

They have urged the courts, before accepting expert evidence, to insist on being told about the known and potential error rates of each field of forensic science.

To bolster their argument, they cite research last year in the US showing the subjective nature of fingerprint matches.

Years after fingerprint experts had made decisions on certain prints, researchers presented them with the same prints and were startled by what happened.

"Two-thirds of the experts made inconsistent decisions; [that is,] they disagreed with themselves," the journal article says.

The same concerns about lack of rigour have been voiced by University of NSW legal academic Gary Edmond, who is a member of the council of the Australian Academy of Forensic Sciences.

He says fingerprint analysis, like DNA analysis, is at the the better end of forensic science. But he says in some areas forensic science is "over-reaching and sometimes just poking around in the dark".

When asked to nominate disciplines at the worst end of the spectrum, Edmond names bite-mark matching, photograph comparisons and footprint matching.

Similar concerns arose last year in the US when a report for the National Academy of Sciences recommended that court testimony by experts should be grounded in science and should acknowledge areas of uncertainty.Read more.


Wednesday, August 24, 2011

How long does DNA last?

The Guardian

Human DNA has been recovered from a Neanderthal fossil 70,000 years old. That's a record, but there may be plenty of DNA recoverable from a human body 10, 50 or even 150 years after death.

The bodies of the Romanov royal family, executed during the Russian revolution, were identified from DNA comparison in the last decade. US scientists recently confirmed the death of the outlaw Jesse James after they exhumed a disputed corpse. Time, says Mark Thomas, a forensic anthropologist at University College London, is not really the problem, even in the tragic circumstances of the Indian Ocean tsunami.

The technique of DNA sampling is less than 20 years old, but has become standard practice the world over. Standards, however, are not quite the same the world over, which may be why a Japanese forensic delegation has announced that it will re-examine all the bodies originally handled by Thai experts, why China has offered to collate the data, why a US team has announced that it will handle the samples from all "foreign-looking" victims, and why the Israeli government sent a 19-member team to help search for Israeli victims.

Both volunteers and resident experts have a host of challenges - stricken relatives, rapidly decaying bodies and damaged infrastructure for a start - but at least time is on their side. DNA is vulnerable. It breaks down in sunlight and water, and there are enzymes that naturally destroy it. But long after death, samples would survive in teeth and bones. Police forensic scientists - often working with only the tiniest samples from a fingerprint or a spatter of saliva - have to worry about the possibility of contamination. But the teams of forensic experts working in Thailand to identify the thousands of victims have no such worries.Read more.

Read all about semen,sperm and DNA specimen here.

All about DNA testing here.

Thursday, February 4, 2010

Biological Facts My Foot! Who Is Dennis Madden?

Hantu Laut

I couldn't believe my eyes when I read the article below published in Malaysiakini.

Contamination a major problem with DNA samples

I refer to the Malaysiakini report Prosecutor: We have semen specimens.

To help the average Malaysian understand what will be going on in the second Anwar Ibrahim sodomy trial, I offer the following biological facts:

1. Contamination is the major problem associated with the collection of DNA samples for analysis.

2. The rectal environment is quite antagonistic to material such as semen.

The bacteria and fermentation process that normally occur in the presence of a high-protein soluble substance like semen would be lead to its rapid breakdown.

Especially so when the samples were collected the following day

3. There would be major DNA contamination from the host and from food waste in the rectum.

Plus the possibility that any DNA present would be partly or wholly broken down.

4. The rectum is quite efficient at rapidly rejecting foreign materials

5. Any intelligent man who was married to a doctor would be aware of the HIV risk from casual sex encounters and would be wearing a condom

So what's this about a 'semen sample'?

Anyone with enough common sense would immediately know the true motive of such erroneous and misleading article. A crude attempt to deceive uninitiated Malaysians into believing that Anwar was framed and incapable of committing such offence by presenting so called expert opinion.No background information of Mr Madden was given on his simplistic opinion.

A check on the Internet for Dennis Madden has produced other names but none on DNA expert with such name.

If Mr Madden is truly a DNA expert, surely, through his extensive work in DNA samplings or other DNA related works his name would have appeared on the Internet in his chosen field of work.

Assuming Mr Madden is a DNA expert than he must be a rookie because his pathetic attempt of presenting an expert opinion falls on the wayside.

It is true contamination is a major problem in any forensic work but with latest technological advancement in forensic science and medicine it is not impossible to analyse and separate DNA samples from other contaminants.

Just like in heterosexual intercourse the rectal environment is not against accepting semen or hostile to it if you are gay and practised anal sex.Not as what Mr Madden perceived would be the case in all cases.

The most laughable of Mr Madden's expert opinion is when he says "Any intelligent man who was married to a doctor would be aware of the HIV risk from casual sex encounters and would be wearing a condom"

"So what's this about a 'semen sample"?

What has risky behaviour got to do with your level of education or the kind of spouse you have?

Mr Madden may not know that today DNA can be manufactured in a laboratory and used to falsify DNA evidence but such technology which was first discovered in Israel has not been used elsewhere.They have also developed new test to differentiate real from fake DNA.So, fake DNA goes out of the window, it can be detected.

Malaysiakini, didn't bother to give Mr Madden's background for reason best known to themselves.

Biological facts, my foot! Who are you trying to fool?

Thursday, July 30, 2009

WHEN DO I HAVE TO GIVE A DNA SAMPLE TO THE POLICE?

Hantu Laut

The law on consent to give DNA samples or not differ from one country to another.

In UK (United Kingdom)or rather in England and Wales the
Criminal Justice and Police Act 2001 changed this to allow DNA to be retained from people charged with an offence, even if they were subsequently acquitted. The Criminal Justice Act 2003 later allowed DNA to be taken on arrest, rather than on charge. Since April 2004, when this law came into force, anyone arrested in England and Wales on suspicion of involvement in any recordable offence (all except the most minor offences) has their DNA sample taken and stored in the database for 12 years, whether or not they are subsequently charged or convicted.

Malaysia passed the DNA Bill in June 2009 that will force criminal suspects to provide DNA samples. The compulsion would be through a court order.

The one below which is applicable in New Zealand would be close to the Malaysian's requirement.

WHEN DO I HAVE TO GIVE A DNA SAMPLE TO THE POLICE?

 What is DNA?
The human body is made up of millions of cells. Each cell contains DNA and each person's DNA is slightly different. This means that your DNA profile can be used to identify you. For example, if the Police found a hair at a crime scene, using DNA they could work out if it belonged to you provided they have your DNA profile. This is why the Police collect DNA and store it on their DNA database.

 Police powers to take DNA samples
The Police can take a DNA sample in certain situations. They do this by taking a buccal test (done by swabbing the inside of the mouth) or a blood test (usually done by a fingerprick) .

A blood sample can only be taken by a suitably qualified person, like a doctor or nurse. You may take a buccal sample yourself. You can choose which way the sample is taken unless a Judge orders otherwise.
The powers the Police have depend on:
• whether you're a suspect in a specified crime and they have evidence to compare a profile to; or
• if they simply wish to include your DNA profile in their DNA databank.

 If you're a suspect
When the Police are investigating an offence they may take a sample from you only if:
• you are a suspect; and
• the offence is serious enough that it will be determined by a jury (an "indictable offence"); and
• they have reasonable grounds to believe that the sample will confirm or disprove your involvement in the indictable offence.

They either need your permission to take a sample or a compulsion order from the High Court. You can speak to a lawyer about giving a sample at any time.


If the offence is a "summary offence" (for example, common assault or wilful damage), the Police can only take a sample if you give them permission.

 Police requests for a DNA sample
When the Police ask to take a sample for DNA analysis, they must give you a written notice and tell you the following things:
• the offence the sample request relates to;
• that they have reasonable grounds to believe the sample will confirm or disprove your involvement in the offence;
• you do not have to give the sample;
• you can change your mind about giving the sample at any time before it is taken;
• you are able to speak to a lawyer before deciding;
• the sample may be used as evidence;
• if you don't consent to giving the sample, and there is good cause to suspect you committed the offence they are requesting the sample for, the Police may apply to the Court for an order requiring you to give a sample.

If you allow the Police to take a sample, your consent must be written and signed or recorded on video. At any stage before the sample is taken, you can withdraw your consent just by saying so.

If you're between 14 and 17 years old, the Police will need both your permission and permission from one of your parents. If you're under 14, the Police may ask you to give a sample but they cannot make you give one unless the offence they are relying on is manslaughter or murder. If the offence they are investigating isn't one of those, the only way they can get a sample is if you let them. They can only take a buccal sample in this case.

 Compulsion Orders
If you refuse to give a sample, the Police will need to apply to the High Court for a compulsion order to take a DNA sample. A notice must be sent to you by the Police telling you they have applied to the Court and you are able to give evidence to the Court opposing the grant of the order.

The two guys from DAP who refused to give their samples can't escape.The police can get a court order to compel them to provide the samples.