"I just had to f-cking kill her". Masa Vukotic's killer explains why he murdered the teen.

On March 17, Sean Price was determined to kill.

The 31-year-old spent the day riding Melbourne’s public transport system – from Albion to Sunshine, to the city, Glenferrie, Footscray and Collingwood, where he boarded a bus to Doncaster shortly after 6pm.

Meanwhile, 17-year-old Masa Vukotic had spent the day at her school, Canterbury Girls’ Secondary College. She had dinner with her family and then went out for a walk.

Fatefully, their paths crossed.

The man who admitted killing teenager Masa Vukotic is due in court for a pre-sentence hearing. @EmilyCAngwin reports https://t.co/1APACQOhXR

— 7 News Melbourne (@7NewsMelbourne) December 14, 2015

Price told the police the teen was “dressed like a yuppie” and “talking to a bird like f—ing Snow White” when he spotted her, News Limited reports.

“F–k this… This is the moment,” he told police.

“I just had to f—ing kill her. She ended up in the wrong place.”

Price – who has a history of violence and had spent more than five years in jail for a series of rapes and assaults – forced the teen into the bushes and repeatedly stabbed her.

The Supreme Court heard today in a pre-sentencing hearing Ms Vukotic pleaded for her life, saying to Price: “No, I’ll do anything you want.”

But the killer was unmoved, pausing only after seeing a man walking his dog. After the man passed, Price continued his gratuitous attack.

Ms Vukotic died after being stabbed 49 times.

Price fled the scene, but stopped to wash his hands in a nearby garden and change his t-shirt.

He told police he had to “make sure she was dead otherwise it’s a waste of time,” the court heard.

News Limited reports Price said he had been planning to stab someone and wanted to target a “rich area”.

“I just hated society. It just built up,” he said.

“I’m going to hurt the f—king dogs… They don’t care unless it happens to them.”

Price told police he planned to kill “another princess” the following day, but changed his mind after someone gave him $50.

“I wanted to f—king stab someone,’’ he told police.

“I was just gonna keep doing it.’’

Instead, he robbed a man and, knowing his time on the run was limited, decided to rape someone so he could have sex before going to jail.

He found his next victim in a religious bookstore in Melbourne’s West.

As he choked and brutally raped the woman, he mocked her, asking: “Where’s your Jesus now?”

The court heard she bravely responded, “Jesus, the Lord, is right next to me.”

The woman fought back and was saved when two people responded to her cries for help.

Price has pleaded guilty to murder, rape, robbery and attempted theft of a car.

This afternoon, Price sacked his legal team, choosing to represent himself.

“I’m guilty of the crime and I wish only to apologise,” he told the court.

“I don’t wish to make any excuses for my actions.”