Mills Jnr gave evidence and claimed the initial encounter was a “chance meeting” with a family friend.
He also said he thought the officer was a mystery assailant.
After the sentencing, Smith said the attack had a huge impact on him and his life.
He said: “I was more than fortunate to survive, but part of me did not survive that day.
“Part of me was lost and two years later, I have started to accept that I will never be the same again.
“My job was a huge part of my identity. I’m unsure of what the future holds for me, and I fear that I will never be able to return to frontline policing.”
Assistant Chief Constable Wendy Middleton described the murder bid as “despicable”.
She said: “Not only has this had an effect on Mark and his family, but it has also had an impact on his close colleagues on the shift and the wider organisation.”
Det Insp Scott Robertson, senior investigating officer, said the father and son were “two very dangerous and callous individuals”.
He added: “Let us be clear that violence towards police officers is a serious criminal offence and anyone who behaves in this way should be in no doubt that we will rigorously pursue them and ensure they are brought to justice.”
