THE case of two girls who battered a vulnerable woman to death in her own home has caused a shocked North-East public to ask, ‘why?’ Chris Webber spoke to a leading criminologist in an attempt to find some answers.

THAT such brutal killings murders could committed by children is so shocking for a good reason: it is so rare.

Although, not as rare as you might think. Between 1994 and 2014 nearly 400 children were convicted of murder in the UK and there were 81 children convicted of the crime in England and Wales between 2008 and 2011.

But, of course, the level of violence used to murder Angela Wrightson puts the crime in a different category.

A category that might include the ten-year-old friends, Jon Venables and Robert Thompson, who murdered toddler Jamie Bulger in 1993 and the two, unnamed Doncaster boys, nicknamed “the devils”aged just ten and 11, who horrifically battered two other children to the point of death in 2009.

Even our region’s most notorious child murderer, Newcastle’s Mary Bell, who killed two boys aged three and four in 1968, had a co-accused, although she was not convicted.

Each of these crimes have three things in common: they involved children, extreme violence and two friends in an intense relationship.

Certainly the two girls who murdered Angela Wrightson had a fiercely tight relationship and their carers and social workers, identifying it as destructive, had tried to keep them apart before the crime.

Even after the murder the younger girl still wrote to her friend and talked about good times they would still have in the future.

Dr Charlotte Barlow, a lecturer in criminology at Birmingham City University, who specialises in co-offending - or criminal - relationships. We asked her a series of questions about the Angela Wrightson case.

Q: Are there any common themes surrounding children who kill? Is it down to having troubled backgrounds?

A: The phenomena of 'children who kill' is actually very rare and there is a tendency to perceive that this is much more common than what it is in reality.

In terms of what may lead some children to do this, particularly in the heinous context of this case, it is often a messy combination of nature and nurture.

Having a significantly troubled background would have undoubtedly been a contributory factor but it important to emphasise that this alone cannot always fully explain these kinds of cases.

Q: How important is the relationship between the teenagers in cases like this? Is it simply a case of one child encouraging the other?

A: The relationship between the two teenagers is a very important aspect of this particular case and it is significant to explore when considering the offending behaviour and how and why it happened.

It is important in cases such as this that the nature of the relationship between the two teenagers is explored beyond the context of the offending act - the whole relationship needs to be explored. It is clear that their relationship was very intense and they relied on each other heavily.

This is hardly surprising, when considered within the wider context of the girls other significant relationships in their lives, such as their difficult and negligent relationship with parents. They arguably had to place more trust and rely on each other.

In co-offending relationships more broadly, there are often different roles that are adopted by all offenders involved and certainly some co-offending relationships can be coercive.

However, in this particular case, it is difficult to say whether one person encouraged the other and I think it is actually much more complicated than this. The girls’ reasons for offending need to be understood within its broader social context, for example, an overly intense friendship, which is arguably the result of a troubled, negligent and challenging upbringing.

Furthermore, another interesting point to consider here is that much of the girl's behaviour within the context of their offending seemed to be dissociated and disconnected from the seriousness of the offence.

For example, taking photographs of the victim and taking a 'selfie' after the murder had taken place. This naivety highlights their lack of understanding of the seriousness of their offending.

Q: The older child was told to ‘f-ing kill yourself’ by her own mother on the day she killed Angela Wrightson (a kind of mother figure herself). Do you think that kind of parenting (the mother was also supplying her daughter with drugs) forces youngsters to have much more intense relationships with the people around them?

A: In some ways, yes, as because they cannot place trust in their caregivers or other adults, this can often lead to such young people developing a replacement- style relationship, whether this be in the form of an intimate relationship or a friendship. It is important to emphasise that this is not only the fault of the mother. I would also question the role of the father, who is often absent from such conversations.