A new law allowing householders to use reasonable force to defend themselves in their homes comes into operation today.
The Home Defence Act was drafted after a heated public debate over the jailing of Mayo farmer Padraig Nally.
Mr Nally was sentenced to six years' imprisonment after he shot dead John "Frog" Ward in October 2004 when he found the Traveller on his premises.
His conviction was overturned when the Court of Criminal Appeal accepted he had not been allowed to use self-defence as an argument.
Justice Minister Alan Shatter said last night there had previously been a lack of clarity in relation to the rights of householders who discovered a burglar in their home and this was now resolved by the legislation.
Meanwhile, the Irish Council for Civil Liberties (ICCL) criticised what it called the "lax" provisions on home defence.
ICCL director Mark Kelly said: "These are lax proposals, which contain insufficiently robust legal safeguards to protect the right to life of householders or intruders."