Detectives investigating the stabbing to death of a suspected burglar said tonight they must determine whether it was "a criminal act" or "self-defence".
Vincent Cooke, 39, was arrested on suspicion of murder after Raymond Jacob was stabbed to death at Mr Cooke's home in the wealthy Stockport suburb of Bramhall on Saturday night.
Mr Cooke, bailed by police today, was at home alone when two men reportedly forced their way into the house before Mr Jacob, from Wythenshawe, south Manchester, suffered fatal knife injuries.
Today police said there will be "strong opinions" on the incident but their job was not to make "snap judgments" but to investigate thoroughly.
Chief Superintendent Rebekah Sutcliffe of Greater Manchester Police said: "It is vital we establish the exact circumstances in which Raymond died and determine whether or not it was a criminal act or of self-defence.
"This process will clearly take time because it is important we do not make snap decisions but investigate fully and without prejudice.
"This is clearly a distressing incident for all concerned - Raymond's family, the occupants of the house and the wider community in Bramhall.
"Due to the nature of the incident, we understand that people will have strong opinions on this subject and this remains a matter of national debate.
"However, I want to stress that my officers have to operate within the law and our primary aim is to establish exactly what happened that night.
"Greater Manchester Police also has a duty to the family of the deceased, the occupants of the house and the coroner to fully investigate what happened to Raymond Jacob."
Mr Cooke was initially home alone at the time of the incident, around 7.50pm on Saturday, but his wife Karen and their 12-year-old son returned during the incident. They escaped unharmed.
Police, along with paramedics, gave first aid to Mr Jacob, but he died shortly afterwards.
He was formally identified today and a post-mortem examination confirmed he died from stab wounds.
Mr Cooke was bailed until October 17, pending further inquiries.
A 33-year-old man has also been arrested on suspicion of aggravated burglary and police have also recovered a white Citroen van being sought as part of the investigation.
Floral tributes to the dead man - referred to as "Ray" and "Raymondo" - were left by family members outside the large detached house. One tribute read: "Love you son. Going to miss you more than anything."
Asked about the incident by ITV News, Deputy Prime Minister Nick Clegg, speaking at the Liberal Democrat party conference in Birmingham, said: "The law is very clear: you have every right to defend yourself, your home, your property, your family.
"The law is really unambiguous on that and no-one should feel they haven't got a right to do that.
"We don't know precisely what happened. Someone died, someone was killed, so I think the police should be allowed to have the space and the time to look into it and make a decision about whether the law has been broken.
"The law is unambiguous: you have a right to defend yourself.
"But clearly, taking the law into your own hands, in individual circumstances, can sometimes lead to circumstances which are not justified.
"I do not know whether that was the case in this particular incident but the law is clear."
It is the third incident of its kind in Greater Manchester in the last few months.
In June, Peter Flanagan, 59, fatally stabbed an intruder at his home in Salford after he was confronted by a gang of masked men wielding machetes.
A month later, florist Cecil Coley, 72, stabbed a burglar at his shop in Old Trafford, Manchester.
Both men were arrested on suspicion of murder at the time but were later released without charge as the Crown Prosecution Service ruled they acted in reasonable self-defence.