Image caption The Justice Secretary says homeowners should know the law is on their side

What happens when a burglary victim fights back and kills an intruder? The Justice Secretary Chris Grayling wants to change the law, to ensure such home owners are treated as victims, not perpetrators of crime - but does the law really need changing?

It had been an uneventful Saturday for Karen Cooke and her family last September.

She left her home in the affluent Greater Manchester suburb of Bramhall to collect her 12-year-old-son Anthony from a friend's house.

While she was gone, her husband Vincent Cooke got a visit from two men saying they were from the gas board. When he let them in they grabbed him and demanded to know where his safe was.

"It was reasonable force" "My husband knew he was going to get killed. That's how he felt. He'd been told repeatedly that they were going to kill him so he had no doubt they would use their weapons. He stabbed the burglar eight times. That included one fatal stab wound. Vincent got wounded as well so it wasn't all one-sided. "It was reasonable force. It was instinctive. And he was being stabbed so he had to take action. "The time my husband spent on bail was quite tortuous. He knew he was a victim of crime but that wasn't the main focus at the time. The main focus was 'has Vincent done anything wrong?' We couldn't eat, we couldn't sleep. We were just all consumed by the notion of Vincent being prosecuted. "We just felt we were out on a limb. We felt very alone. Looking back on those three weeks they were the most stressful, the most traumatic. I know it does seem a short length of time but for us it was absolutely heartbreaking."

When Mrs Cooke arrived home shortly afterwards she walked in on the drama:

"I discovered Vincent being held by one of the intruders at knife-point. A knife fight broke out. One of the intruders attacked Vincent. He lunged at him with a knife. So Vincent had to defend himself and he did so like-for-like.

"As he was in the kitchen he was able to grab a knife himself. He didn't set out to hurt anyone that night. He had to protect himself," Mrs Cooke told Radio 4's The Report.

Vincent Cooke stabbed Raymond Jacob, a convicted burglar, eight times. One of the wounds was fatal.

Mr Cooke was arrested and spent 24 hours in a police cell and three weeks on police bail before learning he would not face charges.

"Vincent now suffers with post traumatic stress disorder - ultimately because he took a life. He's on an awful lot of medication. He's suffering from depression and panic attacks.

"That's something he's finding it very difficult to come to terms with - the fact he was forced to take a life," says Mr Cooke's wife, Karen.

Victims not suspects

If the tragic situation arises where there is a death I think even then the householder should know that the law is on their side Chris Grayling MP, Justice Secretary

Cases like this, where a burglary victim ends up in custody, have prompted the Justice Secretary Chris Grayling to propose a change in the law, which currently states that people can use "reasonable" force to defend themselves.

Chris Grayling wants "disproportionate" force to be legally acceptable instead and prosecutions should be brought only if "grossly disproportionate" force is used.

The Justice Secretary also wants homeowners who stand up to burglars not to be treated as suspects.

"If the tragic situation arises where there is a death I think even then the householder should know that the law is on their side," Mr Grayling told the BBC.

"Before we start to arrest them and put them in police cells and have all the issues about whether they are going to be charged with murder or manslaughter, actually they should know where they are.

"The presumption should be that they are a victim of crime and not a perpetrator of crime."

The Crown Prosecution Service (CPS) in the North West of England says it has to investigate every case thoroughly.

Find out more How does the law deal with burglary victims who attack their intruders? Find out more on The Report on BBC Radio 4 on Thursday, 22 November at 20:00 GMT Listen via the Radio 4 website Download The Report podcast

As well as Vincent Cooke's case, it also had to consider an incident where four men wearing balaclavas broke into the home of Peter Flanagan in Salford. Mr Flanagan stabbed one of the intruders in the chest and he died shortly afterwards. Mr Flanagan was arrested on suspicion of murder.

And in July, four armed men broke into a florist's shop in Old Trafford. The owner, Cecil Colley, stabbed and killed one of them. Neither Mr Flanagan nor Mr Colley were charged.

Sometimes the circumstances are such that what you're dealing with is not self-defence but a vengeance attack Lord MacDonald, Former Director of Public Prosecutions

Although all three burglary victims spent time on police bail the chief prosecutor in the region Nazir Afzal says the decisions were made as quickly as possible and ultimately the law was clear:

"There's nothing courageous about burgling someone's house in the dead of night. It's a very easy thing to do; it's a very weaselly thing to do.

"It's tremendously courageous to stand up to someone who's entered your property, and is after your property, that wants to harm you and your family. The only victims here were the householders," Mr Afzal says.

While there have been high profile cases like that of Norfolk farmer Tony Martin, who shot and killed a 16-year-old intruder, and Munir Hussain who chased a burglar down the road and beat him with a cricket bat, there is no official record of how many burglary victims end up being charged for attacking burglars.

But an informal trawl by the CPS of its own records found only 11 cases in a 15 year period - so does the law already favour the homeowner?

Reasonable or unreasonable?

In 2008, after a lengthy drinking session in a pub in North London, Mark Woods mistakenly tried to enter a neighbour's home - believing it was his own.

"Never intent to cause harm" "We have a new member of the family - a nephew - who carries Mark's name but will never get to meet him. These are the kind of implications when someone gets it wrong. Because Mark was not a burglar. He never was there with intent to cause harm. And yet he's dead. "He'd been very drunk and he'd gone home. He hadn't lived there very long. He'd gone to the wrong door - four doors away from where he lived - and he was trying the key in the lock, trying to get in. The homeowner unlocked the outer door and then opened the inner door. A scuffle then ensued during which Mark was stabbed fatally and he died within a couple of minutes." Regarding the CPS decision not to prosecute: "I was incredulous. We just could not understand how that could possibly be termed self-defence. We just could not understand that at all. I can completely understand over-reacting if [someone is] confronted in their home and they have no other means of dealing with that situation. Completely understand that. "And if Mark had somehow managed to enter that house then I would be on the side of the householder for having defended himself and his family. "The law as it stands at the moment gives a lot of protection for householders."

The homeowner thought he was being burgled and grabbed a kitchen knife. He unlocked two front doors and, believing the bunch of keys Mark Woods was holding was a weapon, he stabbed and killed him. Mr Woods never even entered the house.

The CPS decided the owner defended himself in a very violent confrontation and did not bring charges. A decision Mr Wood's sister Gina Mahn disputed.

"I was incredulous. I don't consider it to be reasonable to unlock doors and go outside to confront somebody.

"I think you're putting yourself in harm's way by doing that when you could quite easily stay inside and wait for the police to arrive. If you're not in immediate danger, why put yourself in that position?"

The former director of public prosecutions Lord MacDonald believes that the law already protects homeowners who act instinctively in the heat of the moment.

He believes if they act in self-defence, "reasonable" force is interpreted very generously in favour of the homeowner.

So what sort of cases were prosecuted during his five years at the helm of the CPS?

"There was a case when a man in a warehouse captured an intruder who'd come onto his premises. He tied him up, threw him in a pit and set fire to him."

"I don't suppose anyone would suggest that was a reasonable or proportionate response and he was prosecuted and convicted," says Lord MacDonald.

"Sometimes the circumstances are such that what you're dealing with is not self-defence but a vengeance attack.

Lord MacDonald and other prominent lawyers do not think there is a need to alter the law, but the Justice Secretary is adamant the change should go through.

It is expected to be debated in parliament before Christmas, but in the face of likely opposition there is no guarantee the new law will have a smooth passage.

Hear more on BBC Radio 4's The Report on Thursday, 22 November at 20:00 BST. Listen again via the Radio 4 website or The Report download.