THEY were Glasgow’s equivalent of Bonnie and Clyde.

Over a period of five years during the Second World War, Robert Thomson and partner Marion Buchan escaped with valuables worth more than £500,000 in today’s money.

However, they weren’t robbing banks and stores like their American counterparts who infamously also murdered nine police officers in the process.

Instead, they preferred the softly-softly approach, breaking into premises when they were closed for business, usually offices, and using a series of skeleton or false keys.

Between 1939 and 1944 they committed more than 100 crimes that left the police scratching their heads.

None of the usual suspects fitted the bill.

In fact, if it wasn’t for two eagle eyed cleaners the two lovers might never have been caught.

At the time Betty McDonald and Nessie McKechnie were working at 19 St Vincent Place in Glasgow city centre.

The building housed the administrative headquarters of several prestigious companies, including the offices of whisky distiller Johnnie Walker, which was located on the sixth floor.

Betty and Nessie worked Monday to Friday and also on a Saturday morning, as was common at the time.

On Saturday, November 18, 1944, the two women arrived for work at 8am and went about their duties, cleaning the various offices over the six floors.

At 11am they were having a tea break when they saw a tall, well-built woman climbing the stairs.

Both were suspicious of her, as no-one usually came into the building on a Saturday.

After a few minutes Betty decided to check the various offices and found the door to Johnnie Walker’s wide open.

She went inside and could see an old cardboard box filled with bottles of whisky and a drinks cabinet lying empty.

Betty phoned a member of Johnnie Walker staff at his home.

He told her to keep an eye on the woman while he telephoned the police.

At this point Betty and Nessie both saw a well-dressed man, wearing a fedora hat, coming up the stairs towards them.

He stopped and told the women he was looking for a particular firm and its offices.

However, they said there was no company by that name in the building.

Undaunted he climbed to the sixth floor where the two women could hear him trying the door of Johnnie Walker.

At this point, the well-built woman reappeared carrying a large suitcase.

Both women realised the couple were planning to steal the whisky.

Betty then called the police and both women made their way outside to wait for their arrival.

The man and woman came out of the building together and headed in separate directions, seconds before the police arrived.

The man walked along St Vincent Place towards Buchanan Street carrying the suitcase.

The woman, carrying a large holdall, headed toward Royal Exchange Square, and Nessie decided to follow her.

Betty told the police that the officers had missed the suspects.

She then jumped into the police car and was able to spot Thomson outside the public toilets on nearby St Vincent Place.

He was standing with the suitcase at his feet and was lighting a cigarette.

Two police officers jumped from their car and arrested Thomson.

Meanwhile Nessie had followed Buchan to Royal Exchange Square.

There she bravely grabbed the woman and the bag, which was full of bottles of whisky.

She frogmarched the suspect back to St Vincent Place where she handed her ‘capture’ to the waiting police and rejoined Betty.

The suitcase and holdall had 22 bottles of whisky and gin. Thomson was also carrying 73 skeleton keys.

The couple admitted breaking into the offices of Johnnie Walker, using the copied keys and stealing the drinks.

Then they also both admitted to carrying out 109 similar crimes since 1939 across the city.

It then emerged why the police had never caught them until now.

Thomson ran his own business in the city and Buchan was a member of staff.

He was the pillar of respectability, a war hero, and had no previous convictions.

Thomson came from a good family and his dad had been a diplomat.

During the First World War, he had seen service in the Highland Light Infantry and later the Royal Flying Corp.

He was discharged in 1922 from the Royal Air Force with the rank of Squadron Leader.

It was then that he set up in business as an outfitter and around 1942 opened offices in nearby West Campbell Street.

He was a married man with two sons, one of whom was fighting in the Middle East and the other a prisoner of war in Japan.

He had been separated from his wife for many years and had been living with Buchan.

She was 33 and had been working for Thomson since she was 17.

It was during her time as an employee that the pair had begun an affair and Thomson had left his wife.

A search was made of Thomson’s office in West Campbell Street where 23 additional skeleton keys were found, together with knives, chisels and a large quantity of other stolen goods, the proceeds of the other break-ins.

It’s thought the pair were heading back to West Campbell Street when the police arrested them.

It also transpired that Thomson was an expert at manufacturing keys to fit any lock.

The skeleton keys were tried at the locations of the 109 break-in’s and were found to open all the doors.

The proceeds of these thefts amounted to more than £10,000 – £575,000 in today’s money.

The amount recovered that Saturday morning from the couple and their office premises was £403 – worth £22,000 now.

When Thomson was charged with the theft at the Johnnie Walker offices, he replied: “You’re quite right. I knew it must come to an end sometime.”

Further investigations revealed that Thomson owned a houseboat at Fleetwood, near Blackpool, bought with the proceeds of his crimes.

This was searched by the local police and found to be a virtual treasure trove of items stolen from the various thefts in Glasgow during the past five years.

More than £2000 of stolen goods – £125,000 today – were found on the houseboat. The couple had been selling the stolen goods on the lucrative black market that existed in wartime Britain.

On the following Monday, the couple appeared at Glasgow Sheriff Court and were remanded in custody to await trial four months later.

They were charged with the 109 crimes and having stolen, amongst other things, 52 fur coats, 11 fur capes, 1000 women’s dresses, more than 300 items of jewellery and a large consignment of headache powders.

They pleaded guilty at Glasgow Sheriff Court to all the charges.

However, because of the seriousness of their wartime crimes the sheriff sent them to the High Court for sentencing.

On Wednesday, December 13, 1944, the pair appeared together in the dock to hear their punishment.

Thomson took the blame for masterminding the operation and said Buchan mainly acted as a look-out.

Trial judge Lord Mackay then turned to the two and said: “This is one of the most amazing cases that has been brought before me in all my years on the bench.

“The audacity of your crimes and the extended period that you have evaded capture is unique.

“I have listened to the arguments, however I have no alternative other than to sentence you Thomson to five years penal servitude and you Buchan to two years imprisonment.”

In 1948, having served their punishment, Thomson and Buchan married at Kelvingrove in Glasgow’s West End.

The pair had made an ideal robbery team because no one would ever have suspected them.

Thomson’s respectable business created the ideal front for his criminal sideline.

It also emerged that a lot of the stolen goods were sold to people that the couple knew, who did not think to question their origin.

Betty and Nessie were nicknamed the Duster Detectives by the newspapers when their story became public.

George Barnsley of the Lanarkshire Police Historical Society, who researched the case, said the police would have been baffled by the crimes.

He added: “It sounds as if they were going round in circles and did not have anything.

“Because the thefts were happening after hours there would be few if any eyewitnesses, while no one would have suspected a well-dressed man in his 50s.

“What the cleaners did was over and above the call of duty.

“It is not known if the women got any award or recognition at the time, but they should have.”