Yesterday a neighbour who lived close to him in the farming village of Banks, Lancs, described him as an introvert who was “clingy” to his mother.

They said his family moved to the area in 2013 when he was aged just seven.

His quiet cul-de-sac – four miles from the scene of the tragedy – remained cordoned off yesterday as police continued to search the £80,000 semi-detached property.

Neighbours spoke of their shock, describing the parents – a Christian “hard-working father and stay-at-home mother” – as “very normal”.

They said their youngest son, who was arrested at the scene of the stabbing on Monday, lived like a recluse.

One man said: “All the time I have lived here, I have never spoken to the lad. I’ve never seen him out on his own.

“I think I’ve probably only ever seen him on two or three occasions.

“They just seemed like a normal family.

“They were very quiet. Dad would say ‘hello and how are you?’ that sort of thing.

“I used to see dad helping his other child in and out of the car.

“But the lad was never out. It was shocking to discover it was a neighbour who had been arrested.”

He spoke of dramatic scenes as around 13 police cars swooped on to the quiet cul-de-sac and went into the house, with a heavy police presence visible overnight.

What we know so far…

• Three children have died after being stabbed
•  Eight other children were injured and five are in critical condition
•  Two adults are also in critical condition after bravely trying to save the youngsters
•  Two yoga teachers heroically helped save some of the kids from the attacker
•  Armed police were called to the scene on Hart Street, Southport, at 11.50am
•  A 17-year-old boy has been detained and a knife seized
•  Chilling footage shows an individual pacing outside a house before the attack
•  Patients have been taken to Alder Hey Children’s Hospital, Aintree University Hospital and Southport and Formby Hospital
•  The attack is understood to have taken place at a Taylor Swift-themed event
•  The singer has said she is in “complete shock”

The resident claimed that the teenager ordered a cab – said to be from the same firm where his father worked – directly to the dance class on Hart Street from outside his house.

Chilling footage emerged of a masked figure, dressed in a green hoodie and face mask, pacing in front of the property 30 minutes before the horror unfolded.

As a child, the lad had lived in a modern, private estate in Wales, where he trained in karate with his father.

They did classes with Sensei Mbakwe, 79, at St Cadoc’s church hall in Llanrumney.

Mr Mbakwe said the boy was a “typical, normal five year old” who continued to train there even after his father fell out with club leaders.

Mr Mbakwe said: “He was a good child, a normal child, who had lots of energy.

“The dad was just a pleasant, normal guy and the son was just a normal five-year-old.”

Mr Mbakwe said the family were nice but the boy’s father fell out with him after he failed him for his black belt grading.

He added: “I’m sad to hear what has happened. It makes me worry about my grandchildren and great-grandchildren with all the knife crime around these days.”

The boy’s older brother is studying at university in the Midlands.

Another former neighbour said: “They were nice children – they were boys at the age where they were bouncing off the walls.

“Always running around screaming and playing football in the garden, that kind of thing.

“They were boisterous boys. I got on really well with them.”

Their ex-next door neighbour, a 55-year-old civil servant, said: “The youngest child was very quiet, an introvert

“He was quite clingy to his mum while his older brother was more boisterous and would stick his tongue out at you.”

Last night he remained in police custody after being arrested on suspicion of murder and attempted murder.

Merseyside Police said social media posts speculating about his name were incorrect and unhelpful.