A former policeman who used his inside knowledge of emergency services staffing in the brutal, premeditated attempted murder of his ex-wife and two children in Brisbane has been jailed for life.

Key points: 44yo Brisbane man tries to kill wife, kids with knives in 2014

44yo Brisbane man tries to kill wife, kids with knives in 2014 Planned attack during police shift changeover to delay response

Planned attack during police shift changeover to delay response Had cheated on wife, pawned engagement ring for prostitutes

The 44-year-old man, who cannot be identified for legal reasons, was a philandering husband who planned to kill his family as a way out of his marital problems, a Brisbane court has heard.

In February 2014, months after he revealed his indiscretions to his then-wife, the 17-year police veteran armed himself with two large kitchen knives and went about attempting to murder her and his nine-year-old daughter and seven-year-old son.

During his sentencing in the Supreme Court in Brisbane on Tuesday, crown prosecutor Dejana Kovac said prior to the attack the man had been seeing prostitutes on a regular basis, had an affair with a colleague, and was a regular watcher of pornography.

Ms Kovac told the court he had even pawned his wife's engagement ring to pay for sex.

"He started to plan to kill his wife and children as a way out of his marital problems," Ms Kovac said.

"The defendant, using his knowledge as a former police officer, determined that the best time to effect the killings would be six o'clock in the morning when the police were changing shifts.

"He armed himself with the two largest and biggest knives he could find in the kitchen — he attacked his wife first because he knew she'd be the hardest person to kill."

The court was told the defendant specifically targeted certain parts of the body, like major arteries, to cause death.

"The attack on her only concluded once the defendant had determined that there was enough blood to indicate the victim would die," Ms Kovac said.

The man then went on to stab his son and daughter who had been woken by the attack on their mother.

Ms Kovac said the girl fought back, begged him to stop and yelled things like "don't, stop — I thought you loved me".

The girl's mother managed to stop the attack by falling over her daughter and then called triple-0.

"The defendant's affect on his victims, on his own family, have been shocking and universally devastating," Ms Kovac said.

Mother carries permanent, gut-wrenching guilt

A victim impact statement written by the man's wife was read by Ms Kovac to the court, where the mother detailed how she had been tortured by the incident.

"I have a permanent, gut-wrenching guilt that I was not able to protect [the children] from their father," the statement said.

"I can never forget the shocking fear on their faces when they saw me.

"My body is littered with scars, I remember counting the number of wounds I had after my stitches were removed — I was chilled by the number — 71."

The mother said her body was a very visible road map of memories that could never be erased.

"I have memories of my daughter's screams of 'please don't kill me, Daddy, please don't kill me, Daddy' — it is soul destroying to see what he did to her little body," the mother said.

Defence concedes attack was 'like a horror movie'

The man's defence barrister Angus Edwards said it was uselessly unproductive to imagine a worse case than this.

"It was like something out of a horror movie," Mr Edwards said.

"It will have an ongoing affect both physically and psychologically on all three of the victims who will no doubt remember this for the rest of their lives."

He told the court his client had a difficult and chaotic childhood and a history of mental health issues, but conceded the maximum penalty of life imprisonment would be appropriate.

The man pleaded guilty to all three attempted murder charges.

Justice Peter Flanagan sentenced the man to life behind bars.