Judge Rishi Seegobin said Mzwakhe Mdlalose, Sandile Mcwabe, and Sphamandla Mkhize had shown extreme callousness and no respect for human life.
They were aged 19, 22 and 23 at the time the crime was committed in February 2011.
“Society expects the courts to punish criminals appropriately for their crimes,” Seegobin said.
He said the victim, 61-year-old Zulu linguist Myrick Hudson-Bennett of Pietermaritzburg, was no match for his attackers, who confronted him in his home with a firearm and knives.
His widow Cheryl told the court that their daughter was returning from England with her fiance to plan their wedding when her father was murdered.
The crime affected them to badly that the daughter stayed on to look after her mother and did not marry.
The Hudson-Bennett family had been taking care of the son of their domestic worker, who had died.
The boy, aged 11 at the time, was the first to find Hudson-Bennett’s body. He was seriously affected and had to undergo psychiatric counselling, Cheryl told the court.
Seegobin said the ages of the accused were considered as a factor in prescribing a sentence. However, the brutality of the crime outweighed the mitigating factors.
Mkhize, who was previously sentenced to 10 years in jail for another crime, was out on parole at the time.