Damian Eric Maxfield, 39, was due to stand trial this week for the 2017 murder of Scott Martin and the life-threatening attack on Mr Martin’s partner, Erelle Mason, at the Blue Bay apartment block.

But a last-minute change of heart saw Maxfield plead guilty to the charges, with sentencing submissions presented in court on Thursday.

Mr Martin’s mother provided a heart-wrenching victim impact statement to the court, describing the “agonising pain” and “huge void” the death of her son had left.

“As a mother I am so empty inside,” Mrs Martin said. “There is a huge void that has taken over my life.

“My son, my baby, is gone.”

Details of the tragic events of January 14 were heard in court, including how Maxfield had been on a five-day meth bender leading up to the murder of Mr Martin and attack on Ms Mason.

The court was told Maxfield had been a former resident of the Halls Head apartments, but was no longer living there at the time of the attacks.

On January 12 he caught the train to the casino in Perth where he gambled, drank, smoked cannabis and took methamphetamine with a man he met in the city.

The next day, while returning by train to Mandurah, Maxfield met an acquaintance and accompanied her to her central Mandurah home.

Witnesses at the address said Maxfield told them he had not slept for five days.

During his visit to the woman’s home he threatened another visitor with a knife and police were called.

Two officers found Maxfield just after midnight, agitated and “rambling” on a nearby street.

He was taken to the local police station, but no charge was laid.

At 1.14am two police officers dropped Maxfield at Blue Bay apartments.

It was where he requested to be taken, and was the address police had on file for him.

How Maxfield entered the secure building remains a mystery.

What is clear is that within about 15 minutes he had entered Mr Martin’s 10th-floor unit and stabbed him twice in the back while he slept on a couch in the lounge room.

Ms Mason, who had been in the bedroom, heard a commotion and went to the lounge room where she spotted the offender.

Maxfield then punched Ms Mason repeatedly, squeezed her throat and hit her with various objects, smashing her teeth in the process.

“I want to kill you,” he said to the woman. “I want you to look at me while I do.”

Ms Mason managed to run downstairs and raise the alarm with a neighbour.

With police en route, Maxfield climbed over the balcony to the ninth floor, entered another unit through a sliding door, and staggered into the shower.

This is where police found him when they arrived at the apartment block.

Mumbling incoherently, Maxfield gave officers a false name in a French accent.

Meanwhile, other officers discovered Mr Martin lying on the floor of his apartment. He had two knives in his back, but was still alive.

Police gave first aid until an ambulance arrived to take Mr Martin to hospital, where he later died.

Counsel for Maxfield said his client had no memory of the murder or attack but was “genuinely remorseful”.

Maxfield is facing a probable life sentence when he next faces court on September 14.

WAtoday