This article contains references to domestic violence, and details readers may find distressing.
The man who killed Hannah Clarke by setting fire to her and their three children considered abducting a previous partner at knifepoint before ending their lives, an inquest has been told.
Rowan Baxter did not go through with that, but on February 19, 2020, his actions caused the deaths in suburban Brisbane of Ms Clarke as well as Aaliyah, six, Laianah, four, and Trey, three.
An inquest that started in the Coroners Court in Brisbane on Monday is set to consider what could have been done to prevent the tragedy.
Baxter was self-absorbed and selfish, thinking everything revolved him and he was "a victim every time", Martin Coll told the inquest on Wednesday.
Mr Coll, who knew the couple for about five years, said Baxter once confided that when another relationship was breaking down years before, he contemplated an abduction at knifepoint.
"He had rope in his car, he was going to take them out somewhere and end it all, including himself," Mr Coll told the inquest.
Mr Coll was also told about a road rage incident in which Baxter said he "jumped" a cyclist and "left him lying there".
Baxter became increasingly suspicious and paranoid about his estranged wife in the months before the attack on Ms Clarke after she left her parent's Camp Hill home to take the children to school.
Ms Clarke said if she didn't do what Baxter wanted after the separation, the kids would pay for it the next day by not getting a treat or going to the beach, Mr Coll said.
He said Ms Clarke phoned him on Boxing Day saying Baxter had abducted Laianah off the street.
Baxter told Mr Coll his daughter was fine and he had gone to NSW.
"That was an escalation in what he was doing," Mr Coll said.
The inquest was told Baxter admitted to a friend he left a recording device at Ms Clarke's house.
"He then overheard Hannah talking to her mother, where they called him a narcissist and other derogatory names," counsel assisting Jacoba Brasch QC said, referring to the friend's statement.

Hannah Clarke with her children Aaliyah, Laianah and Trey on the first day of school 2020. Source: Supplied / Sue and Lloyd Clarke
Lewis Bartlett, who knew Baxter from about 2008 and employed Ms Clarke at his sports shoe store, told the inquest she confided about intending to leave her husband late in 2019, and later said they had what was "classed as a domestic violence relationship".
Baxter had not hit her, but "had done other things" that she did not elaborate on.
Mr Bartlett said Ms Clarke told him that she could not do anything without Baxter's permission, and her husband wouldn't let her wear shorts to work.
In the weeks before the 31-year-old and her three children were set ablaze in a car, Ms Clarke asked Mr Bartlett how to write a will.
"She said if anything ever happened to her she wanted to make sure her children were well looked after and went to the right people," Mr Bartlett told the inquest.
When he replied that nothing would happen to her, Ms Clarke said: "No, he's going to try and kill me."
Ms Clarke said she had told the police her concerns and he thought things would be put in place to protect her.
Mr Bartlett said Ms Clarke had fears about what Baxter would do to her, but didn't think he would harm the children.
"But she did say that he would use the kids against her as almost like a bargaining chip," he said.
Baxter, 42, was also injured in the car fire, but died nearby after stabbing himself.
Ms Clarke died later the same day in hospital.
The inquest continues.
If you or someone you know is impacted by sexual assault, family or domestic violence, call 1800RESPECT on 1800 737 732 or visit In an emergency, call 000.