The family of a Gold Coast detective gunned down in the line of duty say they can finally move on after two of his killers received lengthy jail terms.

The family of slain Gold Coast detective Damian Leeding feel they can now move forward after a man and woman were given lengthy jail terms for their roles in the killing.

“Justice has been done,” the police officer’s sister told reporters outside the Supreme Court in Brisbane after Donna Lee McAvoy and Benjamin Ernest Power were sentenced on Friday.

McAvoy, 40, received life imprisonment with no parole for 15 years for taking part in the armed robbery that Detective Senior Constable Leeding died trying to stop.

Getaway driver Benjamin Ernest Power, 39, was sentenced to nine years in prison.

Forty-one-year-old Phillip Graeme Abell, who gunned down the police officer with a sawn-off shotgun, has already been given a life sentence including 20 years without parole.

“(It’s) definitely a relief that it’s over. I guess we can finally move forward a little bit now in our lives,” the detective’s sister Hayley Sinton said outside court.

Earlier she and mother Julie Waters told the court their lives had changed forever when their 35-year-old son and brother was killed in the line of duty.

“I do not know how anyone could walk past, more than once, a fatally wounded man and leave him to die like you did my son,” Ms Waters told Power and McAvoy as they sat in the dock.

According to McAvoy’s barrister she and her lover Power had needed cash to persuade the state to hand back their child.

The desperate mother had tried to rob a country club six weeks earlier with Abell but they arrived too late to access the safe.

Prosecutors said that experience may have led them to hold up the Pacific Pines Tavern shortly before closing time, about 10.30pm on May 29, 2011.

A customer who escaped unseen alerted police and Sen Const Leeding and his partner arrived 10 minutes later.

Abell shot the police officer in a close-range gunfight as the thieves tried to make off with a 70kg bag of cash and coins.

The detective died in hospital three days later when his life support was turned off.

McAvoy’s barrister Michael Byrne QC said his client was “so sorry” for what happened to the detective but Ms Sinton was unmoved.

“Absolute rubbish,” she told reporters, saying the convicted murderer had refused to look her in the eye in court.

McAvoy was sentenced to 12 years’ imprisonment and Power nine years for their roles in the armed robbery.

Both were given three years for each of seven counts of deprivation of liberty.

McAvoy was also given seven years’ imprisonment for the earlier armed robbery, at the Tallai Country Club in April 2011.

Their sentences are to be served concurrently, while Power must serve 80 per cent of his term after the judge declared him a serious violent offender.

Both have already spent almost three years in jail, meaning Power will be eligible for parole in 2018 and McAvoy in 2026.

For Damian Leeding’s family, it will be too soon.

“It’s not going to bring Damian back so to us, no sentence is really going to be enough,” Ms Sinton said.