The Italian senate has signed into law a widened definition of legitimate self-defence.
The bill, which was promised by far-right Interior Minister Matteo Salvini, passed by 201 votes to 38.
The legislation will limit legal action against persons who fire on an intruder.
"From today, miscreants will know it will be more difficult to be a burglar in Italy it will become a still more dangerous undertaking," Mr Salvini said.
Previously, the law had required proof that an intruder posed an immediate physical threat to the householder.
The new law renders defence legitimate in a person's home against a perceived threat of violence from someone trespassing on their property.
The law also offers free legal aid and defence counsel costs for those who kill or injure an intruder then claim legitimate self-defence.
The law also toughens sentences for theft, burglary and shoplifting, while making release from custody in such cases conditional on payment of damages.
Mr Salvini's far right League party, in a coalition government formed last year with the anti-establishment Five Star Movement, campaigned on behalf of individuals and traders facing justice for killing unarmed burglars.
Magistrates, however, have warned the new law could have dangerous effects, "reducing magistrates' scope for interpretation" of such cases.