Malcolm Webster: Thousand-piece jigsaw on a par with Lockerbie

In what leading counsel described as a "thousand-piece jigsaw puzzle," the arduous process of bringing Malcolm Webster to justice for the murder of his first wife, and the attempted murder of his second, spanned decades and continents.

The investigation occupied some senior police officers for five years and represented one of the most significant prosecution undertakings since Lockerbie, involving specialists in forensic toxicology, forensic accountancy, crash investigations, and fire investigation techniques.

At the case's epicentre was a beguiling figure capable of winning the trust and affection of women, before heartlessly and meticulously plotting and executing their murder. He was a man with gentle, old-fashioned manners, such as standing up whenever a woman entered the room, but they hid the real Webster - a killer, pathological liar, arsonist, thief, and womaniser.

"If ever the expression, 'A wolf in sheep's clothing', applied to anyone, it applied to Malcolm Webster," said Derek Ogg, QC, who led the Crown's case during the trial at the High Court in Glasgow. "He was someone who was both charming and disarming, everyone who described him as an individual used the word, 'charming'."

The well-heeled and well-spoken 52-year-old, Mr Ogg explained, is a man who possesses "innate cunning and cleverness", with a capacity for deluding those closest to him.

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"Malcolm Webster is a very, very clever criminal who has a bent for acting, and a history of it. He was involved in amateur dramatics even though he left school at the age of 15. This is a man who made a murder look like an accident, and it was his cleverness which lay behind that."

Detectives in Scotland were first alerted when a sister of Webster's second wife, contacted police to report her suspicions. But further evidence was required to reopen the investigation into the death of Webster's first wife Claire Morris in a car fire, after the vehicle had left a road in Aberdeenshire.

In 1994 Webster had told police the crash happened when he swerved to avoid a motorcyclist.

Phil Chapman, who was detective chief inspector and the senior investigating officer in the murder case for Grampian Police, said when he looked back at the original investigation "all reasonable lines of inquiry" had been pursued by officers, and experts said there were no suspicious circumstances surrounding the crash and fire that engulfed Ms Morris.

New Zealand police also contacted officers in Grampian in 1999 after allegations Ms Drumm was poisoned and money was stolen by Webster.

But prosecutors in Scotland decided not to re-investigate Ms Morris's death and no further action was taken as forensic technology was not able to help discover fresh evidence.

After one of Ms Drumm's sisters contacted police in 2006, officers turned their attention to a tissue sample from Ms Morris's liver that had been preserved.However, Mr Chapman said specialists had to work out how to "de-wax" the tissue sample, which had been embedded in paraffin wax to preserve it, before toxicology tests to find if there were traces of drugs present could be carried out.

Cutting-edge techniques eventually revealed there was a 92.4 per cent probability Temazepam, which can be taken to treat sleeping problems and for sedation, was in the sample.

Mr Chapman said: "That clearly was a significant development for us in that Felicity Drumm's position was always that she had been drugged and that various tests had been conducted which had detected the presence of benzodiazepines in her body."

Prosecutors in Scotland gave the go-ahead to reopen the case into Ms Morris's death in January 2008.

Grampian's cold-case investigation scrutinised its own reports from the crash on 28 May 1994, an undertaking rendered laborious by the passing of time. Some statements could not be found at all, and it took Mr Chapman and his team several months before they located the statement Webster gave after his wife's death.

The scale of the investigation facing Grampian was huge. Aided by a team of 20 detectives and specialist financial investigators, Mr Chapman realised the inquiries of police and prosecutors would stretch far beyond Scotland, with more than 1,000 people interviewed in all.

Gradually the case, codenamed Operation Field, gathered momentum, and Mr Chapman assembled a picture of a "callous and chilling man", whose darkest deeds were motivated by the most base of desires. The police unit also secured in the region of 90 search warrants for banks, building societies and solicitors' companies for wills to build a financial picture of Webster's life.

A significant focus fell on New Zealand with Mr Chapman and five colleagues spending a month there in 2008.

Some 11 witnesses were brought from there to Scotland to give evidence at the trial, while a video link system was put in place for four other witnesses unable to attend in person.

The investigation, however, was not confined to Oceania. Witnesses and statements were garnered from Australia, France, Spain, Sierra Leone, Peru, and the US, where FBI officials assisted in interviewing ex-pats who had relocated from the Aberdeenshire area. By February 2009, the case was sufficiently strong to bring Webster to court, and charge him. Commenting on the scale of the inquiry, Scott Pattison, director of operations at the Crown Office and Procurator Fiscal Service, said: "If you discount Lockerbie, it's pretty much up there."