The man convicted of killing a family of four while driving drunk in 2015 is arguing his prison sentence should knock off $10 million from a $25-million civil lawsuit filed by the victims’ family.

Three children and their grandfather were killed in a crash caused by Marco Muzzo when he blew through a stop sign in Vaughan in September 2015. He had nearly three times the legal limit of alcohol in his system.

Muzzo pleaded guilty to several counts of impaired driving causing death and bodily harm and was sentenced to 10 years in prison in March.

Criminal defence lawyer and CTV legal analyst Edward Prutschi says punitive damages are not common in civil cases. They are even less common when there has been a criminal prosecution.

Prutschi says Muzzo’s sentence would generally be considered as the punitive element. Muzzo and his family’s drywall business Marel Contractors, which are both named as defendants in the lawsuit, are arguing that the $10 million should be deducted.

In a brief statement of defence filed in Superior Court, the defendants are acknowledging responsibility, so there will be a payment, it’s a matter of determining how much that will be, Prutschi told CTV News Channel. It’s difficult and uncomfortable to talk about, he says, but it’s an actuarial process to determine the value of a life.

“It’s a very cold, calculating scenario and it feels very macabre but it’s a numbers game.”

Daniel Neville-Lake, 9, Harrison, 5, and Milly, 2, along with their 65-year-old grandfather Gary Neville, were killed in the crash. The children’s grandmother, Neriza Neville, and her mother Josefina Frias, were seriously injured.

Prutschi says he expects the final settlement to be on the “lower end” of what is being sought by several members of the Neville-Lake family. He does think they have an “excellent claim” for general damages.

The $25 million is “dramatically large” based on the “enormous real tragedy,” the attention it received and the fact the defendant and his family are extraordinarily wealthy, says Prutschi. Canadian Business pegs the family’s net worth at $1.8 billion.

But courts don’t assess claims based on a defendant’s wealth, he says.

Marel Contractors has been named in the lawsuit because the company owned the vehicle Muzzo was driving at the time of the crash.