Christopher Foster killed his family and set fire to their home because he wanted to "protect" them from his financial troubles, an expert believes.
A coroner has recorded that Mr Foster killed himself and unlawfully killed his wife Jill, 49, and 15-year-old daughter Kirstie.
Criminologist Professor David Wilson said the 50-year-old failed businessman was a "family annihilator" who wanted to take control of his wife and daughter's safety by ending their lives.
The inquest heard he had "severe financial difficulties" following the collapse of his thermal insulation firm, Ulva Ltd, in 2007 and faced losing his £1.2m mansion in Maesbrook, Shropshire.
He had told his GP he felt suicidal four months before the events of 26 August, the inquest heard.
A former business associate and close friend, Peter Grkinic, said Mr Foster had also told him his "only option left was to disappear".
Professor Wilson, who works at Birmingham City University, said Mr Foster's motivation was control.
Professor David Wilson said Mr Foster was a 'family annihilator'
"Christopher Foster falls into a general category that criminologists would call family annihilators," he said.
"In other words, that he will completely eradicate his wife, his children, even animals, associated with the family so that ultimately when they are dead, when they have been eradicated, he can keep control over the process of what might have happened to them, should they have survived."
He said Mr Foster would not have wanted to reveal to his family what his business problems were and the prospect of losing his home would have been the final straw.
"Suddenly the realisation that that roof might not be there any longer is so overwhelming in terms of the annihilator's sense of self that the only way he can resolve that dilemma is not just not to tell his partner or his family.
"He simply kills everyone thus preventing them, as he would see it in a warped way, from being harmed.
"He sees it almost as a way of protecting his family from the harms that might come to them as a consequence of his changed circumstances."
'He loved Kirstie'
Mr Foster's daughter attended the exclusive Ellesmere College, in Shropshire, which is also attended by the Duke of Westminster's children.
But headmaster Brendan Wignall said there had been no indication of the Foster family's financial troubles and that Kirstie's school fees had always been paid on time.
Ellesmere College Headmaster Brendan Wignall said Mr Foster loved his family
He agreed that Mr Foster's motivation was to protect his family.
"I think that the only thing that one can think is that clearly, it goes without saying, he was not of his right mind, because I believe that he loved Kirstie and Jill very much," he said.
"I'm speculating, but I think that he was seeking to protect them, obviously quite incorrectly, from the shame of losing what they were going to lose.
"She was a very popular girl, quite quiet and quite self-effacing, but so far as I know everybody who knew her liked her," he added.
"She worked hard, she was achieving her potential, she was fully involved in life of the college, but horses were the thing for which she lived, it seemed."
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