Liar Liar - [36]

‘And then Denise opened the door as she tried to escape?’ Helen asked.

‘Probably. The frustrated fire would have gobbled up the fresh oxygen in the bedroom – these marks here show how the fire literally exploded into the new space.’

Deborah pointed to a number of long, livid scorch marks across the ceiling.

‘Denise may or may not have regained consciousness after that initial explosion. Either way, if she was motionless in the middle of the room, the fire would have consumed her, setting light to her nightclothes, her hair… If she was still conscious at this point, her body would have gone into a massive state of shock. Cardiac arrest, smoke inhalation, there are many things that might have spared her the worst.’

‘Please God.’

Deborah was already making her way across the gantry and down the ladder to the ground floor. Helen was glad of a moment’s respite from this narrative of destruction. She was used to being at crime scenes, of seeing unspeakable things, but this was different to anything she’d experienced before. Denise Roberts’s attacker was not human and there was no opportunity to escape, defend herself or fight back, as there would have been in a common murder scenario. Hers was an enemy that could not be beaten. Helen, who feared nobody, shivered slightly at the thought of what Denise had faced last night.

Descending the ladder, Helen found Deborah Parks crouching down by the bottom of the stairs. Helen joined her.

‘Your arsonist’s MO is pretty similar,’ Deborah outlined. ‘You can smell the paraffin for yourself and I found a charred packet of Marlboro Gold here. There’s no understairs cupboard, so the arsonist went directly for the stairs themselves, soaking the bottom three steps in paraffin before presumably lighting the delay device and leaving.’

Helen nodded, then said:

‘What are these things here?’

She was pointing at a handful of numbered forensic markers laid out by Deborah around the foot of the stairs.

‘Sodium flares,’ Deborah replied.

‘Matches?’ Helen queried.

‘Exactly. I’d expect to find them on the bottom step, where the delay timer was positioned, but there seem to have been a number of other matches scattered around the base of the stairs and on the floor.’

‘Was that to amplify the spread of the initial fire?’

‘Unlikely. There would be no point putting matches on carpet already soaked in paraffin – our arsonist would know that.’

‘So he or she was just clumsy?’

‘Or in a hurry. We think of these guys as being ice-cool, but they are human beings. Their victim was asleep upstairs but could have woken up at any moment. The arsonist would have wanted to be in and out of the house as soon as possible and when you rush…’

Helen nodded. It was a disturbingly human moment in the midst of a horribly premeditated crime.

‘Other than that it’s pretty much a carbon copy of Tuesday night’s fires. There’s more work to do, but I’m ninety-nine per cent certain it’s the same perpetrator.’

‘Any idea how they gained access?’

‘Looks likely it was via the back door. The front door had the chain on and as yet I’ve found no broken windows or other obvious means of access. The back door was unlocked when we arrived. You’d have to ask family members if the back door was left unlocked as a rule -’

‘Or whether someone unlocked it on their way out.’

If the fire had been started by whoever shared Denise’s bed last night, then it would make sense that he would exit via the more hidden back door to effect his escape. But they were still no nearer finding her mystery lover, so it was all supposition. Perhaps she was just careless of domestic security? Or perhaps just this one time she forgot?

‘Anything else that leaps out at you?’ Helen said, as she made her way to the back door.

‘Nothing tangible yet in terms of our perpetrator. The safety boys putting up the scaffolding disturbed the site anyway, so it would be hard to prove in court that any evidence hadn’t been cross-contaminated or brought in by them.’

Helen swore – that was all they needed.

‘My feelings exactly,’ Deborah returned before moving off to continue her work. ‘I’ll call you when I’m done.’

Helen thanked Deborah and went out through the back door. She did a quick tour of the garden, but, finding nothing of interest on the hard ground, turned to look back at the house. She shivered as she took it in – a modest, family home had been desecrated by fire, turned into a grim curiosity for local youths who lined the streets now, camera phones raised in approval. Denise Roberts hadn’t had many breaks in life, but the cruellest blow had been saved for the very end.

There was only one, tiny glimmer of light in this whole awful story. She had argued with her son and had probably regretted it subsequently, as parents were wont to do. But in doing so she had done him the greatest service a mother can do for her child. She had booted him out of the house to serve her own interests last night, but in doing so she had ended up saving his life.

47

Callum Roberts stared straight ahead as he walked along the gloomy, forbidding corridor. He refused to look at the police officer – DS Sanderson – who kept pace with him. He knew that if he did so, she would start to work on him again, trying to dissuade him from doing this. This was hard enough as it was without her chipping away at him, eroding his determination and preying on his fears. And he knew that if he allowed himself to falter, then he wouldn’t take another step.