Myths and misconceptions about forensic science

[9 April 2009]

An interview with forensic scientist Professor Allan Jamieson.

By Megan Ahern, Crimestoppers UK

In the 21st century, people think that DNA evidence and crime-fighting technology are the be-all and end-all. TV shows like CSI and Silent Witness and their reality cousins constantly top the TV charts - the public certainly has an appetite for entertainment shows based on the science behind crime investigation.

But how much is true and how does it affect our judicial process? This week, Crimestoppers called upon a forensics expert, Professor Allan Jamieson, Director of The Forensic Institute in Glasgow, to sort out the myths and misconceptions in forensic science.

Professor Jamieson has been consulted on a number of high profile investigations. He was one of the defending scientists in the Omagh bombing case and was called to test blood samples from the scene of Princess Diana's vehicle crash.

Biggest misconceptions about forensic science today

Professor Jamieson says that the biggest myths are that “DNA is infallible and the view that forensic scientists spend all their time at crime scenes.” He spends most of his time in the laboratory.

While the rise in popularity of forensic science may lead to more myths, it should also deter criminals. Professor Jamieson warns “it's a lot more difficult now to not leave your DNA at a crime scene [for it to be collected by the police].

“But [there is a] flip side, people who visited the crime scene some time ago could actually be in the DNA that [forensic scientists collect].”

The truth about DNAboost

The figures behind DNA are possibly one of the reasons why it is so trusted. There is a one in a billion chance that DNA found comes from another unrelated person. However, the statistic is only true if each piece of DNA has been properly identified.

A new technology, called DNABoost, which can put together DNA profiles from a mix of samples at a crime scene, may give cold cases new hope. Professor Jamieson warns that the DNAboost process is not perfect for finding the criminal at the scene, “It [can] generate profiles of people who were not involved, [so] you have to be careful.”

The “CSI effect”

The CSI effect has been in the press ever since the shows gained a cult following worldwide. Many experts now believe that the jurors and the public have a distorted view of forensic science and its role in policing. They think the scientists are infallible, quick and that everything is collected and tested.

Professor Jamieson agrees, he says that people expect more from scientists now than ever before, “Sometimes cases that should be successful are not because the jury does not perceive enough scientific evidence. So they feel the case hasn't been made strongly enough.”

How do you become a forensic scientist?

Professor Jamieson had an unconventional journey to forensic science: he began as a geneticist and then moved into medical research. From there he began taking on managerial roles which finally led him to forensic science. Today, he enjoys the challenges it presents. Professor Jamieson adds: “There are still really interesting problems to be solved on a day to day and intellectual basis [in the forensic science field].”

There are two paths to becoming a forensic scientist either via on the job training or academia. You will need an A level in a science subject and four good passes at GCSEs in Maths, Science and English. At university level you will need a first degree in Biology, Chemistry and a postgraduate or a masters degrees in forensic science. The majority of forensic scientists are employed by the Forensic Science Service, by police forces and by regional governments.