Maddison, who was wanted at the time, is said to have harboured a grievance about police and after gunning down Forte held officers at bay on a property in Seventeen Mile for 20 hours before he died in a shootout on yesterday morning.
Queensland Police Union president Ian Leavers, who knew Forte, said everything was being done for his grieving family.
"I have been in contact with some of Brett's family, I haven't spoken to his wife because she is too distraught. They are really doing it tough at the moment," Leavers told the Nine Network.
Forte's best mate says he was becoming increasingly worried about the risks of the job. But Bryce Coventon says his friend remained a committed officer who was passionate about his job.
Coventon said the prevalence of drugs in the Toowoomba area had heightened his friend's concerns about the dangers of being a police officer.
"The last few times I saw him, he did let it (be) known that he was a little bit scared about the job. He was getting worried, there was a lot more drugs and things in Toowoomba," he told ABC radio.
"I know he was concerned but he just didn't know what else to do. But he just passionately loved the job."
Queensland Premier Annastacia Palaszczuk paid tribute to the slain officer as a "fine son" of the police service.
Floral tributes have been left outside the police station where Forte served as a member of Toowoomba's Tactical Crime Squad.
- AAP