My family is unusually jumpy at present. Short of sleep, short-tempered and prone to mild hysteria, our quartet has been joined by a discordant fifth, an invisible player who pops into our minds at any given moment – particularly, it must be said, between 3 and 5 in the morning. He is the burglar whom we found, and fought, in our house.

Two months ago, we returned from a walk. While our daughter went off to kickboxing, my husband and 11-year-old son began to prepare Sunday lunch. I went up to my study to do some work. Walking in, I saw a flash of bright red, and then something that was totally surreal: a young man hiding under my desk.

“What the hell are you doing here?” I asked, as he emerged. He said something about there being someone outside with a gun, and I wondered for a moment whether he was hiding from an assailant. Then we were fighting. It was weirdly intimate – the only time you normally get quite so close to someone is making love, but he was trying to punch me, and I was grappling with his wrists to stop him. Slippery as an eel, and terrifyingly strong, it took all my determination to hand on. From time to time, I’ve done self-defence classes, but in this situation and a small room, any training went out of my head. What rushed in was the berserker fury that pumps you full of adrenalin-charged strength. If he’d stolen computer stuff from my study, there was a good chance he had taken four years’ work on my new novel – and I couldn’t let that happen.  

All this time I was shouting at the top of my voice for my husband. Seconds later, he thundered up the stairs, and then an even more violent struggle took place. The youth was slim, but taller than my 6’2” husband, and very fit. The two of us had him pinned against the banisters (which got snapped in several places) and my husband was roaring,

“What the fuck do you think you’re doing, you bastard?”
“I’ve got a gun,” he said, but I said at once, remembering his previous threat,
“He’s lying.”
I was intent on hanging onto the burglar’s wrists, in case he had a knife, while he and my husband punched each other. The burglar, in retrospect, must have been terrified but looked utterly vicious, snarling and hitting us both. We didn’t feel the blows. At one point, when we were winning, he pretended to cry – which made us both despise him – but the ferocity of our loathing kept us each strangely calm and unafraid. The fury you feel when your private space is invaded and despoiled is extraordinary. I can’t bear to watch violence or cruelty in films, but had I had a knife or a gun in my hand, I would have had no hesitation in using them.

At the same time, we were oddly embarrassed. Grappling with a total stranger in your home feels uncomfortably intimate, and to add to my sense of unreality was the fact that my new novel has a scene in which a woman fights an intruder in the hall of her home, at night. What had inspired this scene is the fact that this was, in fact our second burglary (and third attempt) in six months.

For on Halloween, my husband had woken at 4am and shot out of bed, shouting, after a creaking floorboard and our dog’s insistent scrabbling had alerted him to the presence of an intruder downstairs. We both glimpsed a masked figure running downstairs and out down the side passage which has proved (despite thick security glass, window-locks, London bars and motion sensitive lights) so irresistible to criminals. That time, too, our son William was present, having woken up and hidden in his bed. As far as he was concerned, the first burglary had been a terrifying experience, complete with flashing blue lights and a huge Alsatian dog which tracked our thief (unsuccessfully) down the road. We had improved security, but not put in an alarm, regarding these as a massive social nuisance.

Now, he could hear both his parents fighting another burglar upstairs. He had kept his head, dialled 999 and was politely explaining to the emergency services that we needed the police, when our assailant broke free, breaking a whole row of banisters, and ran downstairs. Instead of running out the door as expected, he went into the kitchen, straight for William.

This was one of the worst few seconds of our life. William had the telephone in one hand, but beside him was a large, sharp knife which had been used for chopping onions. We thought the burglar was going to hold him hostage, and were hot on his heels, now in total terror. He ran at our son, who stood frozen. Then, unexpectedly, the young man swivelled and dived out of a small side window which – rather belatedly – we noticed he had chiselled free of its frame, and escaped minutes before the police arrived, taking with him our lap-top, a modem, an iPod and the contents of my purse but leaving behind in the passage not just my husband’s mobile and Blackberry but, crucially, his own rucksack and baseball cap.

It was the latter which provided DNA, and which has helped convict him when, two weeks later, he tried to burgle my neighbour’s at 3am. I was alone in the house, and unable to sleep because of the anxiety of a repetition. When I heard the unmistakable sounds of stealthy breaking and entering, I flung up the window and shrieked “call the police!” before dialling 999. Satisfyingly, they caught him in the act.

The Kentish Town police have been wonderful. They collected the forensic evidence with meticulous care, and have kept us informed of every stage of the arrest and procedures. The video testimony of my son was elicited with scrupulous rectitude (he was even asked if he wanted to pray before going without me into a room next door, which made him laugh.) When I was taken to the special suite to identify our burglar among nine others on video, the fact that neither my husband nor my son could come at the same time meant that they could not then identify him, for fear of “contamination”. When I asked our detective, DC Longhurst, whether he’d watched ‘Life on Mars’ and felt at all nostalgic for the 1970s methods he said jokingly that “My wife keeps reminding me it’s not a training manual,” before describing how different his generation of policemen are now. They seemed light-years away from the PC plods in TV dramas. I hadn’t expected to get a post-graduate in international politics, or in the case of another detective, a former bio-chemist. I was struck by how interested detectives are in the concepts of justice, and how thoughtful they are about the causes of crime, even such a small-scale one as ours. One said that he had “absolute contempt for burglary. It isn’t a small thing. I’ve seen people die of heart failure a week later, and known perfectly well what it was that really killed them.”

Before our burglaries, I would have thought this a trifle far-fetched. We were surprised to be offered victim support numbers as well as a doctor to check the extent of our injuries (all minor) after the struggle. What we didn’t realise was that the surge of adrenaline that keeps you buoyed up and actually rather happy in the first few hours fades away.

Weeks later, and despite an alarm, we are all sleeping very poorly. Any creak in the floorboards at night, and we’re both jerked awake into a hot haze of blood and thudding hearts. The police are dubious about the wisdom of fighting a burglar, but immensely pleased to have caught him. My husband and I feel nauseous and miserable – and ashamed that such a small thing, as crimes go, should still affect us so. How much worse, then, for our elderly neighbours, some of whom were even more traumatised by their burglaries, and one of whom now lives in a house without natural light as she has all her windows boarded up. We still refuse to have iron bars on all our downstairs windows, which would feel like living in a prison, but have finally got an alarm. It feels like a permanent intrusion into our lives, and a reminder of the ferocious struggle we put up, but it is marginally better than a repeat of it.

William behaved with cool and calm in the emergency but says he felt very small and helpless seeing the man rush towards him, and his school marks slumped in the summer term partly because he just could not get to sleep. He wants to know why we, unlike Americans, can’t keep a gun, and goes into long, violent fantasies about what he would like to do to the burglar. When my children were small, they found books like the Ahlberg’s Cops & Robbers and Burglar Bill funny and reassuring, because they suggested that robbers could either be vanquished or reformed. Now both of them just want to beat them to a pulp.

Perhaps the most distressing thing is that, despite years of hero-worshipping actors like Will Smith and Adrian Lester, our son shows an awareness of race which wasn’t there before. Our burglar was black, and by his act has undone years of discussions about the evils of racism. Having grown up not noticing the colour of people’s skin, he is suddenly very aware of it.

This one teenager has, according to the police, been responsible for perhaps scores of thefts and burglaries in my area of North London, and was professional enough to carry a (brand-new) paintbrush and roller in his rucksack as well as a chisel in case he was stopped and searched. Our detective said he was “a really bad lot”, and the air of triumph when I managed to identify him in a video suite, surprised me. I’m always hearing about how the police don’t seem to care about burglaries, but my experience was the complete opposite. He has now gone to a Young Offenders Unit for three years. Perhaps, given a different life he would (like the thief played by Raffi Gavron in Anthony Minghella’s film, Breaking & Entering) have been a professional gymnast. We all admired his grace as he leapt through our broken window, and the presence of mind with which he scooped up our laptop as he ran. We just wish that, as well as the things he stole, he hadn’t also robbed our son of a kind of innocence.