John Linklater and Caroline Castets consider the mystery of the body on the ben

Why does a man tackle a demanding track up to the peak of a 3756ft mountain wearing city shoes? The answer may be simple. He was cheap. The rag-tag gear that the man with no name was wearing when his body was found on Ben Alder last June would certainly testify to that.

Take the shoes themselves. They were slip-ons, with buckles. Neither trendy nor adequate for the 12-mile hike and climb he had undertaken across the Grampians from the remote station of Corrour east of Loch Treig.

If he was among a group of other hillwalkers who had got off the train, presumably from Glasgow, they would have noticed him. They might have commented among themselves about his thoroughly inappropriate footwear. They might even have made such a remark to him. He would not have struck anyone as likely to make it beyond the nearby youth hostel at Loch Ossian.

Yet he succeeded in achieving his apparent object, outlined for himself in a route to Ben Alder he had marked (or had marked by someone else) on a map he carried along with a compass. If his body had been found in the Sahara, an option offering a similar apparent attraction of extreme remoteness, he would presumably have been wearing wellingtons.

But it was not just the strange shoes that made this an unlikely, even eccentric, expedition. The hillwalking guides, if he ever consulted them, would have strongly advised him to wear fleece-lined ski-type trousers for warmth, and carry waterproof over-trousers. He wore black jeans that no hillwalking club would have permitted.

No fashion jeans, no designer labels (although he took pains to cut most of the labels from his clothes). His were bottom of the range. They were tacky #9 denims bought from the French supermarket chain of Auchan. If this was a statement about his dress sense, he was spelling out cheapskate. He may have had a French connection, but he had failed to collect much in the way of chic.

His Jeremys jeans are exclusive branded for the 50 Auchan supermarkets in France which are mainly concentrated in the industrial North and around Paris. A spokesman for the textile operation of the central buying office said: ''I would say there is a 99% certainty he would have bought them in France.'' The handful of Auchans in Italy and Spain do not carry the Jeremys line.

With the jacket he was making a much more purposeful effort to dress up to the occasion. It was a green waterproof purchased from the camping department of the French sports chain of Decathlon. The poncho was no Clint Eastwood accessory. It was probably just another item grabbed from the Decathlon range. Camping gear. Aspirations towards to country set gear. But still not proper hillwalking equipment.

Neither was the sleeping bag, without a tent. It was a Hellsport product, camping gear that could have been bought from any outdoor store. The oddity is that he could ever have entered such a store and collected such a hopelessly eclectic set of togs.

Do we learn something of all this in the face, reconstructed in wax by forensic artist Di Cullington for the National Missing Person's Charity? Is it the face of a Mr Big who has bought in the bargain basement to cover his traces? Or is it the face of a man who buys cheap because he knows his end of the market?

So, why the intrepid journey to the top of Ben Alder? Why did he not book into a cheap motel in the north of France, around the corner from the Auchan store in Leers, or Villeneuve D'Ascq, or Roncq, or Faches Thusmenil? Lost places off the autoroute for lost souls - surely reasonable enough locations for a suicide. Or was this his only opportunity for his 15 minutes of fame? To die on a Scottish hillside, shot by your own cowboy gun, has more cachet than death in a seedy Zola-esque factory shed.

It was even an economy suicide gun. The replica Remington .44 calibre percussion pistol was almost certainly selected for easy availability and budget price. It could have been picked up for #150-#200 (if he shopped around) at any French ironmongers, sports shop or specialist gun shop. ''They are very easy to find in France,'' said Daniel Cavaye from Expertise Armurerie Bastille in Paris yesterday. ''Up to 10 years ago you could even find them in supermarkets, and you wouldn't need a licence. The only thing is he would have had to know at least something about weapons, because they are quite complicated to use.''

This, evidently, was the one thing he got right. He would pour black powder, a potassium nitrate compound with charcoal and sulphur, into the barrel. A greasy lead ball (up to six) would follow in the revolving cylinder.

Percussion caps would be fitted last. A low-velocity weapon, it would fire at between 800 and 900ft per second, fast enough to kill, too slow to be easily deflected. Heavy and sure into the body. He shot to the chest.

This last detail is a puzzle. The percentage of firearms suicides who shoot to the head or roof of the mouth is much higher.

Two further points may have to be given closer consideration. The recoil would have been expected to send the gun flying out of the hand, but it was found close to the body. A shot would be accompanied by between 12in and 18in of flame from the barrel, which would be expected to burn the sweater the nameless man was wearing and blacken his chest with severe singeing, but there is no forensic evidence on the body to confirm this.

''Murder is not one of my immediate theories,'' says Detective Sergeant Calum MacRae, who has been investigating the case for Northern Constabulary since the body was found last June. ''Once we identify who this man is, it may be different.''