Jamie Lee Dolheguy is on trial in the Victorian Supreme Court for murder after killing Indian-born student Maulin Rathod in July 2018.

Her lawyers argue she did not have murderous intent.

Dolheguy, who was 18 at the time, invited Mr Rathod over after meeting the 24-year-old on the dating site Plenty of Fish, where she had noted she had borderline personality disorder, suicidal ideation and extreme fetishes including bondage.

Senior Constable Luke Colquhoun had been working at the Sunbury Police Station on the night of the killing on July 23, 2018.

He picked up the phone about 9pm and instantly recognised Dolheguy's voice, having been called to her Sunbury home on a number of occasions when she had harmed herself.

Following some visits, Dolheguy had come to the station with cakes she had baked and cards she had written for the officers.

Sen Const Colquhoun said this time, she admitted she thought she had killed a man.

"I think I killed someone. I didn't want to, but I did it," she said, according to a note the officer took at the time, which he read in court on Thursday.

"He came, he didn't seem scared. I strangled him. He's on my bed. It feels so good. I don't want to be a killer."

Sen Const Colquhoun put Dolheguy on hold and conveyed what she had said onto then-Acting Sergeant Kirby Healy.

The officers were unsure whether Dolheguy had actually done what she said and Sgt Healy spoke to her.

"She was pretty calm on the phone," Sgt Healy told the jury.

"I asked her if she had actually done that, and she replied that 'you never believe me, why don't you believe me', or similar to that."

The sergeant gave the phone back to her colleague and drove to Dolheguy's home, where she was standing at the open front door.

Inside, she found Mr Rathod with a phone charger cord wrapped twice around his neck, and Dolheguy began wailing.

"She was yelling out, 'see I wasn't lying, you never believe me, why won't you ever believe me. He's dead, isn't he?'"

Earlier that day, a support worker from the Jesuit Social Services had visited Dolheguy as part of an outreach program and found her "well-rested and in good spirits", the court heard.

The trial continues before Justice Peter Almond.

Australian Associated Press