A FIRE dog discovered the seat of the blaze that killed six children after sniffing out petrol in the hallway of the semi-detached house.
Springer spaniel Freckle and her handler, Dave Coss, were part of the investigation team called to 18 Victory Road, Allenton, on the morning of May 11 last year.
Station manager Matthew Lee told the court how he and his team, which included forensic scientists, first examined the outside of the house and then the inside, starting at the furthest point from where they believed the blaze had begun.
He told the manslaughter trial of Mick and Mairead Philpott and Paul Mosley at Nottingham Crown Court, how there was no sign of smoke or fire damage in the games room, conservatory or kitchen, which were at the back of the house.
But there was evidence of smoke damage to the door that linked the front room to the kitchen and once inside the front room he and his investigation team noticed damage to a front-room window which he concluded would have been slightly open at the time the flames took hold.
Mr Lee, speaking on Day 14 of the trial, said: "That window, only being slightly open, meant the fire did not have a good escape route so, sadly, the smoke went up the stairs and into the bedrooms upstairs.
"All of the rooms upstairs were heavily smoke-logged.
"There was only one seat of fire and that was in the hallway of the house at the front. The heat and smoke damage in the lounge was from a secondary fire where the initial fire was looking for an escape route."
Mr Lee, who has worked for Derbyshire Fire and Rescue Service for 19 years, said once the team's initial "walk through" of the property was done Mr Coss and Freckle were then brought in.
He explained how fire dogs are trained to locate ignitable liquid and that none was found in the lounge area.
A search outside the house also discovered no ignitable liquids on either the doormat or the immediate area outside the front door.
Mr Lee said: "The front door had effectively disappeared, it was pretty much gone.
"The locking mechanism indicated that the door would have been locked. The fact there was more of the handle mechanism and door edge leading to the outside of the property led us to conclude more of the fire was on the inside of the hallway rather than the outside.
"The burn patterns and smoke signs throughout the property led us to conclude that there was just the one seat of fire.
"That was inside the hallway and the fire spread from there.
"We ran the fire dog along the outside doormat and there was no sign of burning nor an indication of any accelerant.
"The dog was not interested in the doormat or the immediate area outside the property."
Mr Lee then said that Freckle was placed inside the front door of the house and at first showed no indication of finding any ignitable liquids.
He said: "We lifted some of the fallen plaster and debris and straight away the dog showed interest.
"We lifted a small section of carpet underlay. It smelled heavily of petrol.
"We ran the dog up and down the stairs and into the lounge area but it just kept coming back to this small section in the hallway."
The jury were shown photographs of the inside of 18 Victory Road that were taken by the fire investigation team, including the bedrooms where the children were found.
In the third bedroom, firefighters who brought the children downstairs emptied drawers and cupboards in the belief that one child was still inside the house.
Mr Lee said: "There was some confusion about an extra child that might have been unaccounted for.
"This wasn't the case but there was some mess made during the search and rescue."
Richard Latham QC, prosecuting, asked Mr Lee to sum up his conclusions about how the fire started.
Mr Lee said: "The fire started in the hallway directly behind the front door.
"Petrol vapours were ignited by a spark or more likely a naked flame deliberately by a person.
"The fire developed at the uPVC front door and quickly spread up the stairs aided by a man-made carpet and wooden materials."
Mr Lee is due to be cross-examined by the defence teams at 10.15am on Monday.
The trial continues.
Philpott, 56, and his 31-year-old wife Mairead have pleaded not guilty to six counts of the manslaughter of their six children.
It is alleged that they were responsible for the deaths of Duwayne Philpott, 13, his 10-year-old sister, Jade, and brothers John, nine, Jack, eight, Jesse, six, and Jayden, five.
The prosecution says the fire at their Victory Road home was started deliberately and was part of a plan to frame Philpott's former mistress, Lisa Willis.
On the morning of the fire, on May 11 last year, Philpott and Ms Willis were due in court over a custody battle with the four children they have together.
The prosecution alleges Philpott was the mastermind of the scheme and that Mairead Philpott and family friend Mosley were "in" on the plan. It says say forensic evidence, which is yet to be heard, will reveal that both Philpott, Mairead and Mosley, 45, had petrol on their clothing.
Mosley, of Cecil Street, Derby, also denies six charges of manslaughter.
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