A builder who knifed six people to death, including his wife and two young children on the island of Jersey, has been jailed for 30 years.
Damian Rzeszowski, 31, snapped after his wife Izabela, 30, admitted having a two-month affair with another man.
He armed himself with kitchen knives and killed her, along with his daughter Kinga, five, and two-year-old son Kacper, at their home in St Helier on August 14 last year.
He also killed his father-in-law Marek Gartska, 56, and turned on his wife's friend, Marta De La Haye, 34, and her five-year-old daughter Julia, who were at the house for a barbecue.
Rzeszowski was convicted of six counts of manslaughter but cleared of murder following a trial at the Royal Court in St Helier, Jersey, last August.
Judge Michael Birt today sentenced him to 30 years for each victim, which are to run concurrently.
According to States of Jersey Police, Judge Birt, who is the Bailiff of Jersey, told the court: 'The horror and brutality of these killings is hard to believe.
'Within a quarter of an hour all six people had died, their lives cruelly cut short at the hand of this defendant.
'The court is in no doubt from the nature of the attacks that you intended to kill all six victims.
'This was not a case of murder - the court found you guilty of manslaughter on the grounds of diminished responsibility - but you still pose a risk of harm to anyone you are in a relationship with.'
The court was told that Rzeszowski was still not fully aware of what he did on the day of the killings.
It also heard that he had sent letters to the loved ones of some of his victims but had not been able to bring himself to write to his wife’s mother.
The killer’s trial heard he acted like a 'pressure cooker with no escape valve' as his marriage collapsed.
The frenzied attacks were launched after Mrs Rzeszowska told her husband she had cheated on him.
Rzeszowski had a history of violence and had as many as 10 fights since moving to Jersey from Poland in 2005.
Solicitor General Howard Sharp, for the prosecution, said Rzeszowski had difficulties controlling his emotions and 'communicating his frustrations and worries' and that violence was part of his character.
After learning of his wife’s two-month affair with another man in June last year, Rzeszowski started going out drinking and had a one-night stand, before taking an overdose of pills on July 19.
In a bid to save their marriage, the couple decided to take their children back to Poland to visit their families.
'However, the problems remained and the defendant visited a prostitute while he was in Poland,' Mr Sharp said.
The terrifying attack happened in the couple’s home in Victoria Crescent, St Helier, on the day they returned from the holiday.
'The state of their marriage was a determining factor in the defendant’s behaviour in June and July last year,' Mr Sharp said.
'He could not face the prospect of a failed marriage.'
On the day of the attack, Rzeszowski got into a discussion with his wife after leaving the children on their own in the house.
Rather than flying into an instant rage, Rzeszowski waited an hour and three-quarters before butchering his family and their visitors.
The court heard Rzeszowski probably attacked his father-in-law first, as Mr Garstka appeared to be be caught unawares while watching Polish TV on his bed.
Toddler Kacper was likely to have been stabbed 13 times with two different kitchen knives while playing with his toys, while the two little girls were each stabbed 16 times.
As she tried to escape her husband’s attack, Mrs Rzeszowska climbed in through the bathroom window and made a desperate attempt to call police using her father’s mobile phone.
But Mrs Rzeszowska dialled 997 - the Polish emergency services number - rather than 999.
Mrs De La Haye, who had visited the house with her daughter for the barbecue, staggered out into the street and collapsed outside the flat.
Rzeszowski admitted manslaughter through diminished responsibility last April, but the pleas were not accepted by the Crown, which argued he was not suffering an abnormality of the mind when the attacks took place.