For 38 years, the Lovers' Lane Killer evaded police. Then he confessed to his daughter.

-With AAP.

Warning: This article deals with accounts of rape/sexual assault and may be triggering for survivors of abuse.

Near a secluded reserve in Melbourne’s south west in 1980, James Dobbie waited in the bush with his sawn-off shotgun.

When a vehicle arrived, Dobbie emerged from the bush. Shotgun in hand, he demanded the couple inside did as he told.

He bounded the teenage boy to a tree and repeatedly raped his girlfriend at gunpoint.

Three years later, Dobbie struck again at the Rowville Police Paddocks, holding a double-barrel shotgun so close to a 20-year-old man’s face he could smell the gunpowder.

Forced into the back of his panel van, he too was forced to watch while Dobbie raped his girlfriend again and again.

“Bye bye,” Dobbie, now a 65-year-old grandfather, told them before fleeing.

He didn’t wait as long for his next attack. A month later, Dobbie struck again – but after pointing his gun through a car window, father-of-two Rodney Mitchell leapt naked out of the vehicle to confront Dobbie and was fatally shot during a struggle.

Dobbie left the scene with a woman who suffered significant cuts and grazes when she threw herself from a moving car to escape.

He then fled to Cape Tribulation in Queensland’s far north east and started a new life.

For almost 40 years, he got away with his crimes. He kept his secret through a marriage, hiding his past from his wife, daughter and stepdaughter.

That was until June 2018, when he confessed to his daughter. He demanded she drive him to a police station so he could confess.

She did, and despite his confession she and Dobbie’s stepdaughter have stood by him.

“I’d just had enough,” he told police. “I want to get it all out now.”

On Monday, Supreme Court Justice John Champion sentenced Dobbie to 31 years behind bars.

The five surviving victims suffered "tremendous pain, suffering and trauma, the effects of which have been felt for almost 40 years and will likely continue for many more," he said.

"Tragically (Mitchell) paid the ultimate price for his bravery in confronting you," Justice Champion told Dobbie.

The predator chose vulnerable victims, used a loaded shotgun to intimidate them and committed violent sexual acts to satisfy his own needs.

The attacks were planned, the time for reflection between each attack only increased his moral culpability.

Dobbie will be eligible for parole after serving 25 years, but the judge acknowledged it was very possible he'd die in prison.

Dobbie couldn't have been prosecuted without his confession to police last year, after an anonymous tip to Crime Stoppers.

That was a sign of remorse, Justice Champion said, albeit one that took 35 years.

His first victim described the attack as a nearly 40-year nightmare that she and her now husband had to relive.

The second woman was then 18 and a virgin. She described being subjected to a violent and humiliating assault and a night of "absolute terror" that she had been determined to simply survive.

Experts revealed Dobbie had been psychologically damaged by his childhood, raised by abusive and heavy-drinking parents.

He was told he was unloved and unwanted, forced to live in a shed from age seven and abused at 12.

At 14 he went into state care, a year later was placed on a farm as a labourer, and was itinerant by 17.

Dobbie has lived a crime-free life since the trio of attacks and is largely rehabilitated, the judge acknowledged.

He'll be 90 at his earliest opportunity for release.

If this post brings up any issues for you, or if you just feel like you need to speak to someone, please 1800 RESPECT (1800 737 732) – the national sexual assault, domestic and family violence counselling service. It doesn’t matter where you live, they will take your call and, if need be, refer you to a service closer to home.