Family annihilation: Fathers who kill their children
Cases of fathers killing their children before committing suicide are relatively uncommon, but in recent years there have been several instances of men killing their families before taking their own lives.
Ceri Fuller stabbed his three children - Samuel, 12, Rebecca, eight, and seven-year-old Charlotte - to death, before jumping from a 60ft cliff.
In the US, he would be known as a "family annihilator".
In England and Wales, figures show that children are much more at risk of being murdered by a parent than by a stranger.
In over two thirds (67% on average) of all cases of children killed at the hands of another person, the parent is the principal suspect, the NSPCC said.
Using figures from the Office of National Statistics from 2007-08 to 2011-12, the NSPCC said that one child is killed at the hands of their parent every 10 days.
While in most cases of family annihilation it is the father involved, there have also been a number of instances of a mother killing her children before committing suicide.
One such case was that of 44-year-old Claudia Oakes-Green who stabbed her two children, Thomas, 13, and Eleanor, nine, to death, before killing herself at their home in Shepshed, Leicestershire in 2011.
'Pawns in a game'
Dr Marilyn Gregory, based at Sheffield University, is an expert on homicide followed by suicide.
She has examined a number of family annihilations in Yorkshire and the Humber, going back to 1975.
Dr Gregory said there are two main trains of thought about why people who kill others then go on to commit suicide.
She is of the belief that family annihilators often kill their families in an "extended suicide" - that once someone has decided to kill themselves, they feel they are free to do "other heinous acts" because the perpetrator knows that nobody can get to him, because he is going to kill himself.
But others who have commented on this behaviour take the view that the person who has killed is then overcome with regret and sees killing themselves as the only way out.
What is common in the majority of cases is that the person involved is often a middle aged, "ordinary" man.
"Obviously it is very difficult for the rest of us to even comprehend how someone can get himself to a state of mind where the children become expendable," Dr Gregory said.
"But sometimes the children in these cases have almost become pawns in a game - the children have become a way of getting back at his wife, a way of punishing her - or they have become belongings of his that he feels he can't leave behind.
"You've often got men who are holding down jobs, they're men who have got a lot invested in their world and particularly, often, in the family on which they then turn the violence."
The trigger to kill is often the failure of the relationship with the mother, or a dispute over the children if the marriage has already ended.
"He will then want to retrieve his control," Dr Gregory said.
"It is a desperate way to do it, and it is perverse, because in retrieving the control he is also losing his own life, but this man has got himself into such a state of mind that says 'if I can't have them, then no one can'.
"In some cases the attitude of the man, from the evidence that is left behind, can be quite punitive.
"He will leave her (the mother) a note saying 'you can't have them now, I've taken them with me'. It's a punitive, 'I'm doing this to get back at you', type of crime.
"But in other cases, there is a notion of misguided altruism, where one man in my sample left a note saying 'the children are at peace now with me', and it is this notion of taking them with them to a better place.
"It is a kind of last desperate act to regain that power and control."