Ms Clarke and her children Aaliyah, 6, Laianah, 4, and Trey, 3, were killed last week when Baxter doused them in petrol and set them alight in a car after ambushing them on the school run. He then took his own life.
Before Baxter married Ms Clarke, he was in a relationship with another woman and had a son, Isaiah who is now in his early 20s. Baxter told Ms Clarke that when the earlier relationship ended, he was going to kill the woman and his son, according to his second wife’s closest friend, Nikki Brooks.
“Hannah had told me that he had a rope and something in his car,’’ Ms Brooks told The Australian.
“He’d driven to do it. He’d prepared what he needed to kill Isaiah and (Isaiah’s mother) and then didn’t do it. Isaiah would have been maybe seven or eight. It was the first time she was going to leave him as well.’’
Baxter told Ms Clarke he had almost killed someone else in a separate incident when Isaiah was a baby, resulting in a conviction for grievous bodily harm, the newspaper reports.
“Hannah just knew there was a road rage incident — he lost his mind and nearly beat someone to death,” Ms Brooks said.
“He would make it out to be someone else’s fault, of course — someone did something and he acted the way he did because he had a baby in the car.’’
After years of abuse, Ms Clarke separated from Baxter in November last year and the two had been working on custody arrangements.
“We said, ‘Han, enough is enough,’” Ms Brooks told A Current Affair.
“It was getting bad and we had to get her out of there.”
Ms Brooks said when Ms Clarke hid at her house following the separation, she seemed “happy” and “relieved”.
“She stayed with me and we felt safe. He didn’t know where I lived. She just looked relieved and she just seemed really happy. She knew she made the right decision,” she said.
Ms Clarke’s brother Nathaniel spoke to the ABC’s 7.30 program on Tuesday, saying his sister had received “amazing support from the police”.
What “cut” him the deepest, he said, was that Baxter had made his wife and kids suffer before their deaths.
“It wasn’t quick. It was planned and executed,” he said.
“He had a plan that night when he called the kids and he was a blubbering mess. He knew what he was doing then. He had it all planned out, he knew what he was doing the following morning.
“He couldn’t even do it quick. That’s the worst thing. He made them suffer, and her.”