ALEX Reuben McEwan told police he had been waiting to "kill someone” all his life - and student Eunji Ban died because she was the first person he saw early one morning.
In an audio recording played to a jury in Brisbane Supreme Court, Mr McEwan also told police he "bashed the s*** out of her face” and spoke of a demon tormenting him.
"It's been troubling me my whole life,” the former Ipswich man said as he rode in a police car on November 25, 2013.
The day before, Ms Ban left home at 3.56am, walking through her apartment building, seen on security footage shown to Mr McEwan's murder trial.
Ten minutes later, a man the prosecution alleged matched Alex Reuben McEwan's description left Spring Hill Centrepoint apartments, at 69 Leichhardt St.
"She just screamed for help. Next thing I was strangling her,” Mr McEwan told police.
He told cops he felt "psychotic” and as if he was watching somebody else attack the 22-year-old student.
"I feel sorry for the Asian girl, and her family.”
Mr McEwan has pleaded not guilty to murdering Ms Ban.
Jurors at Brisbane Supreme Court were shown CCTV and police crime scene images on Tuesday.
The images showed the remnants of Ms Ban's life laid out on pavements, stairs, and a nearby park.
There was her TJS Services shirt, so "saturated with blood” a police officer said part of it had turned from white to maroon.
There was a Samsung mobile phone and its detached blue and turquoise phone case found beside Albert St.
There was a pocket ripped from a shirt, near pools of blood and disturbed soil.
And there was Ms Ban, found in Wickham Park with dirt on her tracksuit pants, abrasions on her stomach, rips on her clothing.
Alex Urquhart, originally from Biloela, became friends with Mr McEwan after getting to know him at Brisbane's Fairfield Skate Park.
He said Mr McEwan was occasionally aggressive, but just in the sense of "horseplay” with mates, and never violent towards women or strangers, Mr Urquhart said.
Prosecutor David Meredith has said there was no dispute about who killed Ms Ban, so a key issue would be whether Mr McEwan was of sound mind when he killed her.
"It didn't feel like it was him who did it. It felt like he was possessed,” defence counsel John Allen told the jury.
The trial continues.