He was known simply as 'The Big Fella’ and was head of the CID in Glasgow for 15 years.

Detective chief superintendent William Ewing was always immaculately dressed and often taken for a doctor or a businessman.

His father was the local inspector in Stranraer in the south-east of Scotland and he was bought up in the local police station which had its own house.

He joined the City of Glasgow Police in 1911 and quickly impressed his superiors.

By May 1921 he had become a detective and was involved in one of the most infamous crimes of the time.

Senior IRA figure Frank Carty had escaped from a prison in Derry and fled to Glasgow where he was later arrested in a house in the Springburn area.

The following day he was taken by police van to Duke Street prison in the East End of the city.

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Because of the terrorist threat a number of armed officers travelled in the same vehicle as an escort.

As the van pulled up outside the jail a large number of gunmen opened fire, killing inspector Robert Johnstone and injuring sergeant George Stirton.

However, they failed to free Carty and instead fled on foot.

Ewing was one of the first officers on the scene and was involved in the arrest of the main suspects.

However in a sensational development at a trial in the High Court in Edinburgh, all 13 accused walked free.

By 1932 Ewing had reached the rank of detective lieutenant - the equivalent now of detective chief inspector - and was to take charge of what would prove to be two of his biggest cases.

That year he led an investigation into a shares scam in Glasgow involving a bogus company where victims had been defrauded out of more than £800,000 - the equivalent of £62m today.

The complex trial lasted a record 33 days, yet only one person was convicted and he was sentenced to just three years.

The judge in the complex case later paid tribute to Ewing's endeavours in solving the case when he said: "The facts of it were far beyond the capacity of the human mind to carry and retain."

By then the City of Glasgow Police was frequently called upon to help other forces investigate major crime on their patch.

On September 29, 1935, two bodies had been found dumped in a stream in Moffat, Dumfriesshire, including a severed human hand and arm.

Other packages with body parts lay scattered nearby. 

The local police immediately sought assistance from the City of Glasgow force and Ewing travelled to Moffat the following day.

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The case was dubbed the 'Jigsaw Murders' by the press because 30 blood-soaked packages had been found dumped in the water, containing a total of 70 body parts. 

While in Moffat, Ewing read about a missing maid, Mary Rogerson, 20, who was last seen alive on September 14.

She worked in the household of Dr Buck Ruxton in Lancaster.

Mrs Ruxton had also not been seen for some time. Her husband was now a prime suspect in the Jigsaw Murders investigation.

Following his arrest in October that year Ewing ordered a top to bottom search of the doctor’s house.

If fingerprints from one of the bodies and fingerprints on articles in the house were found to be identical, it would establish beyond doubt that the deceased had lived in the house. 

Every article likely to bear fingerprints was examined and taken back to Glasgow to be photographed. 

Comparing the prints found on the articles with those of Miss Rogerson confirmed her identity.

Ewing and his team were later praised by J. Edgar Hoover, then director of the FBI in America for their ground-breaking work.  

Ruxton had murdered his wife as she returned from a night out in Blackpool. 

Caught in the act by Miss Rogerson, he asphyxiated her, fractured her skull and stabbed her.

A Manchester jury took less than an hour to find Ruxton guilty of both murders. 

In the words of the trial judge, the fingerprint evidence of the City of Glasgow Police had proved the most damning of all.

Ruxton was hanged on May 12, 1936, at Strangeways Prison in Manchester.

The director of public prosecutions in England also wrote to Glasgow's chief constable congratulating Ewing and his men on their investigation.

In 1937 he was made head of the City of Glasgow CID, a post he would hold into the early 1950s.

By 1945 he had been promoted to the newly created rank of detective chief supt. and had also been awarded an MBE.

That year he led the investigation one of the most callous and cold-blooded murders ever committed in Glasgow.

Two railway workers were shot dead in a botched robbery in which the gunman escaped with only a few pounds.

It was Monday, December 10, and clerkess Annie Withers, porter William Wright and junior porter Robert Gough were on the late shift at Pollokshields East Railway Station, near Albert Road.

About 10pm that evening the door burst open and a young man brandishing a gun appeared.

He immediately fired at Annie Withers  and she fell to the floor.

Gough threw his body across Annie in a bid to save her.

The gunman killed her with a second round of shots as she lay screaming.

He then turned towards 15-year-old Robert and shot him twice.

Crucially Robert gave a deathbed statement describing the killer, before he died two days later.

Ten months after the double murder Charles Templeman Brown became the prime suspect.

The 21-year-old railway worker lived with his mum in Brisbane Street in Battlefield, a mile and a half from the murder scene.

Realising the police were on his tail, he handed himself into a passing beat cop near his home.

Brown went on trial at the High Court in Glasgow on December 9, 1945, where he was found guilty of the double murder and sentenced to death.

However, a petition to save him from the noose was successful and the execution was commuted to life imprisonment.

During his time in the force Ewing was also responsible for arresting a cop killer and a killer cop.

In 1946 retired detective James Straiton, 62, had been shot dead while trying to foil a burglar who had tried to rob a neighbour’s house in Edinburgh Road, Carntyne.

John Caldwell, a 20-year-old soldier, who lived in Bridgeton, Glasgow, was quickly identified as the killer.

Caldwell stood trial at the High Court in Glasgow in June 1946 where he was found guilty and sentenced to hang.

On midnight on July 29, 1950, the crumpled body of Catherine McCluskey, 41, was found in Prospecthill Road.

Ms McCluskey, a single parent with two children, had been in a relationship with a serving police officer, constable James Robertson.

However, the 33-year-old married father-of two denied knowing the victim.

His beat partner, PC Dugald Moffat, confessed he had been covering for Robertson for some time to allow him to slip off for couple of hours, when things were quiet, to see a mystery woman.

That's exactly what had happened on the night of the murder. 

Robertson had gone off to see his mistress around 11pm and turned up again for duty two hours later.

The period covering the death of Ms McCluskey.

He also owned an old-fashioned Austin saloon car.

A quick search of the undercarriage revealed blood and fragments of Ms McCluskey’s flesh, hair and clothes. The cops had their man.

Constable Robertson stood trial at the High Court in Glasgow on November 6, 1950, charged with murder.

He denied murdering Ms McCluskey, saying instead that he did not know her well and gave her a lift.  

He said he reversed back and accidentally knocked her down. 

After a trial lasting seven days, the jury took just 64 minutes to find the PC guilty of murder on November 13, 1950. 

He betrayed little emotion as sentence was passed and he was led down to the cells.

PC Robertson was the only serving policeman in Britain to be executed for a crime committed while on duty.

Typical of Ewing he had not allowed the fact that Robertson was a colleague to interfere in the process of bringing him to justice.

In March 1951 the police chief retired after 40 years’ service and died in 1979 in Mearnskirk Hospital in Newton Mearns.

At his retirement speech at Glasgow police HQ he hadn't told the usual jokes or reminiscences.

Instead, he called for more officers on the beat and tougher sentences for the criminals.

Ewing also recalled with some satisfaction that most of the people he had put behind bars had ended up destitute, murdered or hanged, adding: "Very few died peacefully in their beds."