Michael Peachey died following a "harrowing" engagement with police, in Gunnedah in central NSW on May 21 2021, during which he was tasered, pepper sprayed and restrained.
At the time the 27-year-old was most likely suffering from an undiagnosed psychotic episode and violently resisted the efforts of officers to subdue him, an inquest into his death concluded on Thursday.
Mr Peachey's cause of death was found to be a combination of factors, including having been restrained in the face-down prone position, which led to a cardiac arrest.
In delivering her findings, Deputy State Coroner Elizabeth Ryan found officers involved had breached police training and procedures by leaving the young father in the restraint position for longer then necessary.
On the night of his death, police responded at roughly 8:29pm, at which stage Mr Peachey struggled with the two officers, ending up in the house of a neighbour who was not known to him.
"He struggled vigorously against the attempts of the two police officers to restrain him," Ms Ryan said.
Following the prolonged engagement, Mr Peachey was restrained and placed face down on the floor in the prone position at roughly 8:48pm, after which he experienced a fatal collapse about 9:13pm.
Ms Ryan noted three police officers and two paramedics who were present when he died, all failed to notice that Mr Peachey had stopped breathing until it was too late to do anything to save him.
Despite claims by paramedics and police Mr Peachey could not be moved from the restraint because he continued to present threat, the inquest concluded that from 9:07pm he had stopped moving almost entirely and was most likely exhausted.
"From that point onwards, consistency with NSW Police Force training required that he be moved into a safer position on his side or back," Ms Ryan said.
Ms Ryan accepted that by this time, the officers who first responded to the situation were "physically and emotionally exhausted" having engaged in the struggle for roughly 40 minutes without any back-up.
Neither the officers present, nor the paramedics, realised Mr Peachey was no longer resisting or posing a danger to them and should have been moved out of the prone position, the inquest found.
"During the critical minutes before it was realised that Michael was not breathing, it does not appear that any monitoring by the paramedics was occurring at all," Ms Ryan said.
Ms Ryan described as a "very live issue" the manner in which those experiencing severe distress are dealt with by emergency services, particularly police officers being the first to respond.
"It places a high demand on police resources and police officers are not trained mental health professionals," Ms Ryan said.
Ms Ryan recommended NSW Police Commissioner Karen Webb consider forming an independent policy on prone restraint, which clearly communicates the risks and the importance of moving a person from the position at the earliest opportunity.
