A Nova Scotia man convicted in the 2011 accidental shooting death of his 20-year-old son has been sentenced to four years in prison.

In sentencing Michael Paul Dockrill on Friday, Nova Scotia Supreme Court Justice Joshua Arnold said the man "fired blindly. That figure could have been anybody."

"This is precisely why gun crimes in Canada are treated so seriously," he said, reading from his sentencing decision.

In April, a jury found Dockrill guilty of criminal negligence causing death and careless use of a firearm for shooting his son Jason in June 2011.

Dockrill and his son were trying to fend off a home invasion at their house in Lakeside when Michael Dockrill opened fire. He said he thought he was shooting at an intruder. 

Arnold said Friday that when Dockrill shot at someone he was "wantonly reckless as to whether they died." Dockerill didn't know he had shot his son until he went outside.

Arnold described a parent killing his own child as "probably the very worst of tragedies."

Dockrill declined to address the court.

Mandatory minimum

The crime carried a mandatory minimum sentence of at least four years, as outlined in legislation passed by the former Conservative government.

But Brian Church, Dockrill's lawyer, had argued in December that such a sentence violates Dockill's charter rights and had a gun not been used, his client would not be facing the mandatory minimum. 

The prosecution was seeking a sentence of between five and seven years.

Arnold ultimately rejected the defence's charter challenge. On Friday, he reviewed past cases involving criminal negligence causing death. 

He also reviewed testimony, including some that indicated Jason Dockrill was dealing drugs out of the home and his father didn't interfere.

Arnold also said there were previous break-ins at the home and at one point police seized 17,000 grams of marijuana. 

The CBC's Blair Rhodes live blogged the sentencing.