The mother of a man who was accused of murder after stabbing a teenage burglar has travelled to London to campaign for a change to the law.
Charges against Omari Roberts from Nottingham, who was confronted by 17-year-old Tyler Juett during a break-in, were dropped earlier this year.
His mother Jaqueline McKenzie-Johnson said the 23-year-old had unnecessarily been put through a "stressful ordeal".
She wants the "reasonable force" law redefined to protect victims better.
'Ridiculous and outrageous'
Mr Roberts was confronted by two teenage burglars when he arrived at his mother's house in Basford for a lunch break in March 2009.
He picked up a kitchen knife to defend himself, fatally wounding Juett and injuring his 14-year-old accomplice.
Later that year, the Crown Prosecution Service (CPS) decided to charge him with murder and attacking the younger burglar.
But in April 2010, when Mr Roberts was due to stand trial, he was told the charges had been dropped.
Nottingham Crown Court heard the case was abandoned after the 14-year-old burglar changed his story about being chased by Mr Roberts, and also admitted he had been carrying a knife and "would have killed".
Ms McKenzie-Johnson called the CPS's initial decision to prosecute "ridiculous and outrageous".
She said: "They knew my son called paramedics, that he did first aid, CPR, on the young person, that the injury was sustained in a struggle, and that he did not go out with the intention to harm someone."
She added: "I think that the current legislation expecting occupants to use reasonable force is confusing and it's a very woolly area.
"We should not be using the words 'reasonable force'. It is an unreasonable situation so why are we expected to behave reasonably?
"There needs to be more support for occupants and homeowners and the law should be more weighted on their side."
She is calling for the coalition government to amend the law, as had been previously proposed by the Conservatives.
Ms McKenzie-Johnson handed in her "Safe as Houses" petition, signed by 2,000 people, at Downing Street.
In England and Wales, anyone can use "reasonable force" to protect themselves or others, to carry out an arrest or to prevent crime.
Householders are protected from prosecution as long as they act "honestly and instinctively" in the heat of the moment and if they genuinely believe they are in peril in their own home.
A Ministry of Justice spokesperson said: "We are currently looking at this area with other interested government departments and the enforcement authorities to see whether the existing law or the way it is interpreted by the enforcement authorities needs to be strengthened."