Tragic echo down the years

This long-forgotten and inglorious episode in RAF history started innocuously enough that Saturday when a Mr John Walker left his home at 2 Peffer Bank - a tenement that looks out over Edinburgh's Craigmillar public park - to answer an air raid alarm.

A member of the Auxiliary Fire Service, Walker was joined in his car by three fellow fire service members before the quartet sped northwards down Duddingston Road, past the Polish army camp opposite Duddingston loch before turning into Willowbrae Road.

Already they could see in the approaching darkness searchlights poking long silver fingers skywards in search of the German aircraft reportedly heading for Leith.

As the four firemen entered the eastern half of Willowbrae Road where it merges with Northfield Broadway, Walker was forced to brake to an emergency stop by a uniformed figure who had loomed suddenly into the path of his vehicle.

A shout of ''halt!'' was immediately followed by the muzzle of a .303 Lee Enfield rifle which was thrust through the open window of Walker's car.

The rifle-toting figure ordered the AFS officer to drive into nearby Northfield Farm Road and, on arriving there, the four men in the car were ordered out and told sharply to put their hands on their heads.

To the collective amazement of all four AFS men, the gunman was wearing the uniform of an RAF sergeant. The sergeant told Walker and his colleagues that he would not hesitate to shoot them all if they ignored his commands. As though to accentuate the point, an attempt by Walker to retrieve his identity card from his tunic pocket brought the rifle muzzle between his eyes.

Walker then detected a strong smell of alcohol from the sergeant's breath. Yet, just as suddenly as he had appeared, the RAF gunman lurched away and disappeared into the darkness.

In fact, the Royal Air Force gunman was Sergeant Alexander McPherson, a local man who had just returned home on leave to Edinburgh from his base in the blitz-torn south of England where invasion-scare anxiety in the wake of the Anglo-French defeat in France by the Nazis was at fever pitch.

The sergeant was a drill instructor and one of the finest NCOs in his squad. However, McPherson's CO also testified that the sergeant was prone to be impetuous. McPherson had been told by his military superiors that it was permissible to shoot at any vehicle whose driver failed to stop after receiving three warning commands to do so.

This rule may have been eminently sensible in the streets of Dover or the lanes of Sussex, places where the sudden appearance of Germans was at least feasible, but it made much less sense in a relative wartime backwater such as Edinburgh's Willowbrae Road. After leaving Walker and his AFS colleagues, McPherson again went back to Willowbrae Road where he was confronted, once more, by a rapidly approaching car.

The RAF man later claimed that the car was driving with blazing headlights in breach of wartime regulations. Because of this illicit illumination and the German aircraft droning overhead, the RAF man concluded that the vehicle contained Fifth Columnists who were trying to guide the bombers towards Leith Docks by using the car's headlamps.

At this point McPherson alleged that he also shouted halt the prescribed three times. When the car occupants appeared to ignore his challenges, the sergeant fired once, shattering the car's windscreen.

But, far from containing German agents, the car was conveying the assistant chief constable of Edinburgh City Police, Mr Robert Chisholm Thomson OBE, who had overall wartime command of air raid precautions in the capital and was answering the same air raid alert as fireman John Walker and his colleagues. Mr Thomson was seated beside the driver, Constable Robert Knox, and in the rear of the car was Sergeant Harold Smith.

Both Knox and Smith were later adamant that they heard no challenge, a fact they put down to the noise of their car's engine.

Nevertheless, that single .303 round inflicted a horrific wound on Mr Thomson's lower jaw, prompting PC Knox - who had dropped Smith off to arrest McPherson - to drive to Edinburgh's Royal Infirmary.

Meanwhile, Sergeant Smith courageously struggled with McPherson in the middle of Willowbrae Road, eventually wrenching the rifle from the RAF man's grasp.

McPherson remained unrepentant over his actions, according to one witness who had left his home in nearby Paisley Avenue, attracted by the commotion.

Meanwhile, Assistant Chief Constable Thomson lingered for three days before dying from pneumonia. So was Scotland robbed of an outstanding policeman. A man of immense potential. He was a native of Lilliesleaf in Roxburghshire and joined the Edinburgh City Police as a constable in the early 1920s, where he soon caught the eye of Chief Constable Roderick Ross whose personal protege he soon became.

During a rapid round of subsequent promotions the able young Borderer was sent to study the individual police box system first pioneered in Britain in Sheffield.

On Thomson's recommendations, these boxes soon appeared in Edinburgh streets where they still remain at various sites throughout the capital. Indeed, ironically enough, one of the best preserved examples of these mini police stations still stands at Duddingston crossroads - only yards from where McPherson fired that fatal shot that killed Thomson.

In the 1930s, he had not only staked his place as the capital's chief constable-in-waiting by taking an LLB degree at Edinburgh University, but had also been awarded the OBE by King George V and Queen Mary in recognition of the policeman's time as their personal bodyguard during the couple's stay at Holyrood House to mark the 1935 Royal Jubilee celebrations.

With one single rifle shot all this became immediate history.

Two months later at Edinburgh's High Court before a special wartime jury of only seven people, McPherson pleaded not guilty to culpable homicide.

Much was made by the RAF sergeant's defence lawyers that he had been subjected to a constant barrage of propaganda films about Fifth Columnists and saboteurs being sent to spearhead the impending German invasion of Britain.

The jury concurred with this plea for, while finding McPherson guilty of culpable homicide, they made a strong recommendation for mercy on the grounds that McPherson was ''a somewhat unfortunate testimonial to the efficacy of the propaganda concerning Fifth Columnists and the high level of military alertness currently being displayed by HM forces in southern England''.

Despite the plea for mercy, Sergeant McPherson was jailed for six months. Arguably, he had done more to harm Scotland's war effort by killing Assistant Chief Constable Thomson than any of the Fifth Columnists he himself so despised, ever did.

So, although next year will see not only the millennium being celebrated but the 60th anniversary of Winston Churchill's gallant Battle of Britain ''few'' - pilots such as Bader, Johnny Johnston, and Scotland's own Archie McKellar DFC - it will also be the anniversary on Wednesday July 13, 2000, of an altogether less glorious episode in Royal Air Force history, an episode that nearly 60 years later still has lessons to offer about the dangers of authorised arms being left in the hands of the unstable on the streets of Scotland.