Squad cars blocked the normally peaceful Burgh Road, in Blackheath, London. The blue lights were switched off but, had they been on, wouldn’t have looked out of place among the festive illuminations strewn over trees in many front gardens, lighting up the dark hours pre-dawn. The handsome red-brick houses were all large, neat, detached, built for affluent Victorians during the heady decades before the First World War. The period properties were what kept Blackheath such a desirable address still.

Along the tree-lined street there were few net curtains to twitch at the gathering crowd of police officers. Instead, neighbours peered, bleary-eyed, around blinds, or pulled back wooden shutters that matched the original sash windows of their homes. Adults shooed their little ones away, but stayed rooted to the spot themselves, clinging to each other for safety behind the glass. The children probably didn’t need much persuading to stay away, overjoyed at an excuse to unwrap their presents without their parents wearily trying to go back to bed just a little longer.

Christmas had indeed come early for them.

Chief Inspector Paul Ogundele checked his watch – 3.47 a.m. – and got out of his car to take charge of the scene. He noticed how some neighbours, bolder than their counterparts, edged to their front door and stood watching, poised to bolt at the first sign of trouble. He’d have to remind uniformed officers to send them back inside for their own safety.

According to a laminated poster still attached to a fence, Burgh Road had been closed a fortnight earlier, too; that time for a festive street party for neighbours to get to know one another and to allow youngsters to play in the road without fear. Cheery, multicoloured bunting still hung from lamppost to lamppost, dripping in the pouring rain. Below it, in swags, was yellow police tape.

Outside the cordon, paramedics hunched in their ambulance, steaming up their windows as they waited to be told when it was safe to do their jobs. They wouldn’t be setting foot anywhere until the police’s armed response unit had finished securing the place and given them the nod.

Chief Inspector Ogundele took it all in in a second. He ducked under the tape and strode over to a uniformed officer standing stoically, pretending she didn’t notice the waterfall running in front of her face from her hat.

‘Sergeant Hussain. What’s the situation?’

‘Gunshots were reported at 3.20 a.m. by a Mr Alan Jackman, of 17 Burgh Road. At least two shots fired within his neighbour’s home at number fifteen. Mr Jackman told the control room during his 999 call that his neighbour has a shotgun and regularly goes clay pigeon shooting. He also says he heard “shouting and one hell of a row” which woke him immediately before he heard gunfire.’

As the officer spoke, she indicated over to a man in his early fifties whose pallor matched his prematurely grey hair. He was still in his blue towelling dressing gown and matching pyjamas, but stood defiantly to attention at his front door, as though afraid of showing weakness. Especially in his new, bright yellow Simpsons slippers.

‘Residents have been warned to stay indoors, sir,’ added Sergeant Hussain.

The chief inspector made a noise of impatience. People so rarely listened to orders, curiosity generally overcoming fear. Some residents even held up their mobile phones, filming the excitement and no doubt live-streaming it on Facebook, Twitter, and any other social media they could think of.

‘What do we know about who lives in the building?’

‘Number fifteen belongs to Mr Benjamin Thomas, forty-eight, and his wife Dominique, forty-four. According to the neighbour, they have two children, Amber, who is between seven and nine – the neighbour isn’t sure, and Ruby, a teenager of about sixteen. Checks have confirmed that Mr Thomas has a licence for a shotgun, which is kept on the premises.’

Had Benjamin Thomas had an accident? Discovered burglars and taken a potshot? Or perhaps been shot at by armed thieves? Did the gun go off by mistake? Or had he gone crazy and killed or injured his wife, children and himself? Murder/suicide was a terrible thing, and rare, but not unheard of by any stretch of the imagination. At this time of year there was generally a spike in domestic abuse, due to people being in close proximity for longer periods than they would be at other times of the year.

Just what happened to the family inside number fifteen?