Marcus Rappel bought an axe less than an hour before he murdered Canberra mother-of-three Tara Costigan after making repeated threats to kill the next woman who took out a domestic violence order against him, a court has been told.
Ms Costigan sought protection from Rappel the day before her death after her ex-partner allegedly grew increasingly violent when their relationship broke down.
Rappel, 41, had been joined by another former partner when he was served with the order at Civic police station on February 28 last year and told her:
"I did say if another girl slapped a DVO on me I would kill her."
Rappel had then thrown the document out his car window and became frustrated as he told the woman: "I should kill that bitch for what she did".
Later that afternoon he is alleged to have bought an axe from Bunnings Warehouse at Tuggeranong before he drove to the Calwell house where Ms Costigan was feeding their week-old baby daughter and stormed inside.
Rappel then fatally struck her and assaulted two family members who tried to intervene.
A couple of hours later the woman has claimed she got a text message from Rappel that read: "she's dead".
A series of events surrounding the murder are now the subject of a three-day disputed facts hearing – held when the defence and prosecution cannot agree on the details of an offence – in the ACT Supreme Court.
Crown prosecutor Shane Drumgold on Monday outlined a string of incidents in the lead-up to Ms Costigan's death and said she had been "absolutely congenial" towards Rappel after their relationship broke down.
She had applied for the order after Rappel showed signs of violence, abuse and threatened to harm her family members in text messages sent to her uncle, Michael Costigan.
Ms Costigan had explained to Rappel she would take out the order until he got help and that he was allowed to collect his belongings and see their daughter for supervised visits.
"Her compassion towards him was met with acrimony," Mr Drumgold said.
He said CCTV footage showed Rappel had driven back and forth outside the house 13 times within 46 minutes as he waited for Ms Costigan's brother to leave before he went inside.
Defence barrister Steven Whybrow said Rappel wouldn't have been able to tell whether the man's car was there from the street and he would argue there was another explanation for why he had repeatedly driven past the house that afternoon.
Rappel's former partner, whose name has been suppressed, gave evidence he had grown angry and frustrated after he was served with the order and had accused Ms Costigan of using the system to keep their daughter away from him.
"He said he'd lost his family and it was all over for him," she said.
The woman said his pledge to kill the next woman who took out an order had been made in a sarcastic voice.
She said the pair had gotten back together but she had broken up with Rappel the day of Ms Costigan's killing.
Ms Costigan's brother, Derrick Filby, told the court he'd spoken about his sister with Rappel several months before the attack and recalled he said something like: "The next woman who puts a DVO on me, I'm going to kill her."
He said Rappel, who had been driving at the time, appeared angry, violent and psychotic and had lost his temper before punching the car's windscreen.
Tensions flared in the courtroom, which was packed with Ms Costigan's family and friends, when Mr Filby was asked, under cross-examination, roughly where that punch had landed.
"What does it matter?" Mr Filby said. "He physically lost his shit and punched the windscreen."
On the day of the murder he'd overheard Ms Costigan tell a visiting midwife she was worried and concerned for her safety, Mr Filby said.
A case worker at the Alexander Maconochie Centre gave evidence Rappel had claimed Ms Costigan had been the second woman who had lied to get an interim domestic violence order taken out against him.
"You have no hope if you're male," Rappel allegedly told him.
"God I wanted to hurt the bitch, and I know what I was doing, so I can only plead guilty."
At another meeting days later Rappel allegedly said: "I don't want to deny I did anything as I took the life of someone."
Rappel is due to be sentenced later this year.
The hearing, before Justice John Burns, continues.