How Scots soil expert helped solve Karen Buckley murder case

In April 2015, Professor Lorna Dawson was enlisted by Police Scotland to examine traces of dirt found on the boot of  21-year-old Alexander Pacteau.

The former public schoolboy from Bearsden was later convicted of killing occupational therapy student Karen Buckley shortly after meeting her in a Glasgow nightclub.

Prof Dawson’s lab work proved that Pacteau had recently been at a lock-up he had rented at High Craigton farm on the outskirts of the city, where he burned a mattress and clothes before concealing Buckley’s body inside a barrel.

Crucially, her analysis also found traces of soil on the killer’s car that had been missed when he had it cleaned.

It proved the vehicle had been at Dawsholm Park in Glasgow where Karen’s handbag was dumped.

Prof Dawson was drafted in by police soon after the 24-year-old Glasgow Caledonian University student was reported missing by her friends on April 12.

“It was right at the outset,” said Prof Dawson, who is Head of the Soil Forensics Group at the James Hutton Institute.

“The great thing about Police Scotland is that they include their own scientists from the Scottish Police Authority forensic services, so the biologists, the chemists, they regularly attend forensic strategy meetings.

“They also ask, where appropriate, the external experts such as myself.

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“In this particular case, I was phoned [and told] that poor Karen had gone missing and might still be alive and we’ve got the boots of the last person she was seen with on CCTV.”

Karen had met Pacteau at the Sanctuary nightclub in the city’s West End, before he offered to drive her home, instead killing her in his car on nearby Kelvin Way.

“They had retained one of the boots for DNA,” said Prof Dawson. “You would usually do the DNA first before any soil examination is done, but in this case there was a hope that it might lead to where she might be held captive and she might still be alive.

“Sadly that wasn’t to be and it was a case of doing things as quickly as possible.

“The priority was, can you tell us where she might be and where he had last walked?”

She says police and scientists involved in criminal investigations are fortunate in Scotland to have an extensive soil archive, which can be matched with 14,000 locations across the country.

She said: “We carried out surveys in the 1970s and repeated the surveys in the late 2000s at every 10km point across Scotland plus any other types of soil that weren’t covered by that grid survey.

“All those soils were analysed for their elemental composition, their pH, the carbon content, their texture plus lots more information. 

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“When I get a sample, I can compare the results with all the information from 14,000 locations.”

The sample on Pacteau’s boot was a match for an area around High Craigton Farm in Milngavie.

“There were two areas there that shared the characteristics of the boot and that supported a piece of intelligence the police were investigating at the time,” she said.

“Someone had told them that he kept some equipment in a lock-up at that same farm. 

“It’s often supportive information that gives them greater confidence that something has happened at a particular place or not.

After Karen’s body was recovered and the case became a murder investigation, Prof Lawson was then tasked with analysing soil found on Pacteau’s car tyre.

She said: “His car had been seized and we went down and we sampled that car at Gartcosh  –the blood and the DNA and any fibres or hairs are recovered.

“We would then look at any soil and vegetation after that.”

Prof Lawson said the evidence linking Pacteau to the murder of the Cork student was “overwhelming”.

She said: “We found soil under the tyres.

“He had taken the car to get washed and valeted but we still managed to recover soil that the washing process had not removed.”

Pacteau was jailed for a minimum of 23 years in September 2015, with Judge Lady Rae describing him as a “cold and calculating man”.

Prof Dawson is currently involved in four cases and spends around 80 per cent of her time on police investigations across the UK, with the remainder of her time teaching at Robert Gordon University, where she is an honorary professor in forensic science.

She says she tries not to get personally involved in the human side of the work she does to ensure she can help police find out what happened in an objective way.

"When we get the samples we give them an anonymised code so that we don't associate with the human story until the very end," she said.

"I'm privileged to have the job that I do because there is no better thing you can do than seeing the impact of the science and how it impacts on the criminal justice system in getting as close to the truth as we possibly can, to bring some closure to the families who are affected by these tragedies."