Mariano Grixti, 49, of Żurrieq has been jailed for 25 years after he was found guilty of an attempted double murder in October 2005.
In a trial by bench, Mr Grixti had pleaded not guilty to attempting to kill Joseph Mifsud and his 15-year-old son Redeemer.
He shot them following a heated argument over the building of a boundary wall in a field near Zurrieq. Both were critically injured.
The farmer said he fired five shots in self-defence after the Mifsuds started throwing rocks at him.
Mr Justice Michael Mallia found Mr Grixti guilty or attempted murder and jailed him for 25 years.
Drs Franco Debono and Charmaine Charett appeared parte civile for the victims while Philip Galea Farrugia appeared for the Attorney General's office. Dr Joe Brincat was defence counsel.