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How DNA breakthrough has transformed police investigations at Northumbria & beyond

25 Apr 2018 10:00 AM

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A scientific breakthrough more than six decades ago continues to shape the way officers at Northumbria Police and beyond solve crime.

Today marks International DNA Day, which celebrates the discovery of DNA's double helix in 1953 and the completion of the human genome project half a century later.

The idea that crime-fighters in the North-east could one day be able to identify an individual from the smallest trace of their blood, saliva or semen used to be a thing of fantasy.

But now it’s an everyday reality as police forces up and down the country use complex science to convict offenders, free the innocent and track suspects’ whereabouts with unprecedented accuracy.

Whether it’s investigating burglary, car theft or sexual assault, DNA evidence continues to be a key forensic tool used on an everyday basis across Tyneside, Wearside and Northumberland.

“DNA profiling has been an important tool in the investigation of crime,” said Kirsty Potter, Northumbria Police’s Scientific Support Manager.

“It has helped us to collate profiles of crimes and criminals and use them to search and detect offenders in cases where it may not have been previously possible. 

“During the early years, a substantial amount of DNA was needed via body fluids such as blood, saliva and semen to be able to obtain an offender’s DNA profile for comparison against a suspect or the National Database. 

“But advances in technology have enabled DNA profiling to develop into increasingly sensitive techniques that are now able to detect tiny traces left at scenes and on exhibits that may previously have gone undetected. 

“In fact today’s DNA profiling analysis is routinely so sensitive that interpretation is often very difficult, as background DNA is also picked up from touched surfaces and previous legitimate contact. 

“The complexity of contemporary DNA interpretation has led to developments in software and even specialist analytical techniques, such as the ability to detect only male DNA amongst an abundance of female DNA.

“These advancements ensure that the forensic potential of DNA evidence is still maximised in all criminal investigations.”

DNA was first used in a police investigation back in 1986 to solve the murder of Dawn Ashworth, a teenage schoolgirl who was raped and strangled in Leicestershire.

Now, after decades of scientific advancement, more than 5.3 million individuals in the UK are thought to be retained on the National DNA Database, which was set up in 1995.

As of December 2017, around 80% of profiles on the National DNA Database were thought to be male, the majority of which aged between 25 and 44.

Samples of blood, saliva and hair can all be analysed at a crime scene to help officers obtain a DNA profile, as well as miniscule flakes of skin and even fingernails.

The type of crime in which DNA is used to solve across the Force area continues to broaden too.

“Every day our Scientific Support Department considers using forensics in investigations ranging from burglary to murder and everything in between,” Mrs Potter added.

“Sensitive DNA profiling allows us to identify who may have held a weapon, who may have grabbed the clothing of an assault victim, and even identify offenders who may have deposited DNA in places even they could not have expected.

“Without doubt, DNA remains one of the most powerful forensic science tools in the investigation of crime.”

Among the high-profile recent cases in which DNA profiling helped bring an offender to justice was the conviction of double rapist Eric McKenna, of Clarewood Court, Newcastle.

Last month, the 59-year-old was jailed for 23 years after he was convicted by a jury of two separate stranger rapes in Gateshead and Newcastle in the 1980s.

It wasn't until 2016 that McKenna emerged as a suspect when he was arrested by neighbourhood officers for urinating in a neighbours plant pots following a dispute. He was cautioned for harassment and routine DNA swabs were taken following the incident.

However, when they were processed in the police system they flagged up as exact matches for DNA recovered in the two historic rapes.