TO their neighbours in Buckingham Terrace, Comely Bank, Mrs Bertha Merrett and the 17-year-old son she doted on and fondly called "Donnie" were just an ordinary mother and teenage boy.
Today though, the name Donald Merrett rests alongside some of Britain's most infamous killers – in Scotland Yard's notorious Black Museum, a tall jar filled with formaldehyde sits on a shelf, containing the two severed and scratched forearms of Mrs Merrett's beloved Donnie.
It all began on March 17, 1926, as the financially fastidious Mrs Merrett opened one letter from her bank warning she was overdrawn. There could only be one explanation.
The shot that rang out that morning must have stopped the neighbourhood in its tracks, but Donald – who bought the .25 Spanish automatic pistol using money looted from his mother's account – was nothing if not a very quick thinker. Within moments he was telling the daily cleaning woman, "Rita, my mother has shot herself", blaming "money matters" for her apparent suicide attempt.
His wounded mother was rushed to the Royal Infirmary where she later told one friend: "Donald was standing beside me. I said, 'Go away Donald, and don't annoy me'. Next I heard was a kind of explosion. Suddenly a bang went off in my head."
She told her sister: "Did Donald not do it? He is such a naughty boy."
Although his desperately ill mother was left paralysed down her left side by the bullet, Donald didn't linger at her bedside. Instead, he became a regular at the notorious Dunedin Palais de Danse in Picardy Place, where an accommodating hostess could be bought for 30 shillings a night, half price for an afternoon.
Despite the ten shillings a week allowance he had received from his mother, he showered the girls there with gifts, sometimes whisking one off for an afternoon on the motorcycle he'd bought a fortnight before the shooting for 28.
His 55-year-old mother survived for a fortnight before meningitis claimed her life. With no husband to look after her affairs – he had gone missing in Russia during the revolution – her sister organised her burial in a grave in Piershill Cemetery.
No longer able to forge his mother's cheques, Merrett moved to Buckinghamshire. He was preparing to attend Oxford University when, eight months later, police came calling.
He appeared at the High Court in February 1927, charged with murdering his mother and forgery. To many it probably seemed a cut and dried case, but the jury were swayed by Merrett's clean cut, middle class poise, a brilliant defence performance which focused on the facts and not his client's dubious morals. They took just 55 minutes to return a verdict of not proven on a charge of murder, but guilty of fraudulent use of his mother's bank account.
Merrett served a year in prison, and the Edinburgh incident proved to be start of a bizarre lifetime of deception, theft, frauds, illicit deals and murder. First though, he had to come up with an entirely new persona, a new identity to detach him from events in his native city.
He went to live with a wealthy friend of his mother, a bogus aristocrat who called herself Lady Menzies – perhaps the inspiration for him to reinvent his own identity and change his name to Ronald John Chesney. Soon her 17-year-old daughter had caught his eye and they married in a Glasgow registrar's office.
The pair were sleeping rough in a tent when Merrett inherited a massive 50,000 fortune from his maternal grandfather. Suddenly he had everything he yearned for: a mansion, a Bentley, and a private plane. His sleek yacht became a common sight on the Mediterranean where, in 1936, he dabbled in smuggling and gun-running to Franco's Spain.
His money was quickly spent but not before Merrett had organised an 8500 endowment on wife Vera to be paid to him upon her death.
But that was put aside while Merrett's life took another twist. The outbreak of the Second World War saw him commissioned into the Navy, where he quickly earned an almost legendary reputation for being fearless.
He also revelled in the opportunities to smuggle and defraud whatever and whoever he could.
Post-war, he found his way to Buxtehude, near Hamburg, where the Royal Navy officers employed in dismantling the remains of the German fleet welcomed his cheerful manner, thrilling tales and flair for finding virtually whatever anyone needed, from champagne to petrol.
Only once, during a game of bridge, was his past ever hinted at, when one player recalled him suddenly blurting out: "Oh, that was the year I murdered my mother".
Despite his appearance – at one stage he was 22 stones and described by that bridge partner as having mean, piggy eyes and a mean, vindictive expression – Chesney was a hit with German Gerda Schaller, the woman he moved into his quarters at British taxpayers' expense.
Life was good. Merrett's deeds in Edinburgh were in the past, and as Chesney he revelled in a string of unscrupulous deals on food, drink, jewellery – almost anything.
Trouble was looming though. By 1954 Interpol were investigating his activities. His smuggling days were at an end and money was tight. Chesney needed money, fast, and his thoughts rewound to Vera and that endowment.
He used a forged passport to make his way to Vera's home in Ealing, where he greeted her with two bottles of duty free gin.
She was unconscious through drink by the time he plunged her body under the water of her bath. When her elderly mother stumbled upon the scene, he dispatched her too by smashing a coffee pot into her skull.
This time it didn't take police long to see a connection between their deaths and the man, who, with nearly 10,000 at stake, clearly had a motive for wanting his wife dead.
Five days later, Merrett was back in Germany, but the police were on his tail. In a quiet wood by the River Rhine, he put his pistol in his mouth and pulled the trigger.
Police still wanted to close their case. They had found flesh under "Lady" Menzies' fingernails, and they wanted to inspect Merrett's badly scratched forearms as final proof of his guilt.
Today, those dismembered arms are in a clear jar on that shelf in the Black Museum.