`Suspect on his way to Santa's Grotto'

Retailers may complain about recession on the high street this Christmas, but there's still one business that's booming: shoplifting.

ADRIAN STANDS motionless behind a display of men's underpants, staring fixedly at an elderly gentleman fishing through a rack of socks. He looks innocent enough, but within minutes he's been singled out from the swarm of last-minute Christmas shoppers in Selfridges on Oxford Street. "You get a second sense about people," says Adrian, darting from behind his Calvin Klein camouflage to another vantage point - a potted palm beside one of Selfridges' grand white pillars. "Sometimes you can't pretend to be a shopper; you have to find a spot to get a really close view of the suspect," he explains.

It's hardly the high drama of Cops, but Adrian Pannett, 38, Selfridges' chief store detective, has his moments. A high-speed chase through women's separates, perhaps, even a scuffle in Santa's Grotto. Recently, a woman stuffed so much merchandise down her leggings, they ended up around her ankles when she tried to sprint down Oxford Street. Another woman embarrassed Adrian acutely by shouting "Rape!" as he chased her out through the door. And there was the man who tried to leg it with a solitaire diamond worth pounds 7,000. When Adrian collared him in the perfumery department, he threw it high in the air, shouting "This one's on me, darling".

Two days before Christmas, the season of reckless criminal activity has reached its zenith. Peace and good will don't extend to crime, which flourishes from the end of November until the end of the New Year sales - shoplifting offences rise by 10 per cent. A retail crime survey carried out by the British Retail Consortium says there's been a huge increase in theft in the last year - it is up by 42 per cent, costing shops nearly pounds 47m. Shoplifting last year cost pounds 1.83bn, including crime prevention measures.

Last year, Asda lost pounds 1.3m to theft. It adopted a "zero tolerance" policy, now adopted by other stores, whereby shoplifters face a bill for compensation, paying around pounds 130 per offence to cover legal fees.

Most shops are gearing up for a grimmer festive period than usual, after a year dogged by threats of a world-wide recession. Even in Selfridges, the crowds seem thinner than usual. Pannett has caught 30 per cent more shoplifters this Christmas than last - though it's hard to know whether financial gloom has tempted more ingenues, or surveillance has improved. Selfridges has invested in 160 state-of-the-art security cameras and has 12 store detectives on the shop floor.

In the hi-tech security centre, lined with television screens, Adrian, who used to work in the Marines, shows me a "Best of..." video: a series of fumbling opportunists caught on camera. In some cases their sheer gall is impressive: people who stalk out of the food hall with a frozen turkey pushed down their trousers, or pile 20 designer jumpers inside a coat. You almost pity the nervous ones, looking like frightened rabbits as they pick up clothes or books, shaking, looking around, then putting them back. "They're the ones who've been hit by adrenalin," says Adrian. "They can't see anything. Their heart's racing. You can tell it's getting to them."

Once they're caught, Adrian takes them to a holding-room until the police arrive. It sounds pretty grim: cameras, no door handle on the inside and no windows. Adrian says: "Sometimes we do close the door on them - we've had people who pull out knives, syringes."

After 18 years Adrian has a pretty good idea of the dominant categories that "lifters", as he calls them, can fall into. A noticeboard behind him is covered with details of what he calls your classic Prolific Lifter - someone who steals for a living, sells merchandise on, often has to support a hefty drug habit and has been prosecuted several times. There's also the Opportunist Lifter - anyone from a housewife to a businessman; and the Label Lifter - out for a specific fashion item. And there's the Emotional Lifter, who steals because they're clinically depressed or distressed. These Adrian says he doesn't much enjoy catching.

He talks about the time he caught a young woman stealing some clothes. She was suffering from post-natal depression. "It was the worst job I've ever done - I didn't want to give evidence against her," he says. As a father himself, he sympathises with parents who are distraught to discover that their teenager has been caught swiping a Nike sweatshirt or a Mac lipstick. "Sometimes you just think, `There but for the grace of God go I'."

He tilts his head and listens to a tiny radio earphone. "Suspect in Santa's Grotto. Blue coat and hat. Heading away from the toy department." He races up the escalators and fights his way through a crowd of children. Too late; the suspect has disappeared. "He was off his head. Drugs or drink," says a security guard.

Still, Adrian's had his piece of action for the day. "It can be boring when there's nothing happening," he says. "I love it when it's busy. There's a message in your earphone. You get that adrenalin buzz..."