Asia was described by her teachers as "very bright", Jairus was said to have "great enthusiasm for life", and Grace as a "bright, friendly and polite child who was full of life". Judge Coate stated it was evident that the deaths were not accidental, based, among other things, on the fact that Mr Osborne armed himself with sufficient ammunition to fire four lethal rounds. He left a note in his pocket in which he made reference to his children in what Ms Coate said appeared to be his last words, which was full of vitriol and anger towards a former partner. The note said: "Please let his find my (former partner) ... You twisted your story to take revenge on me. You know how wrong your motives are. To get things go in your favour I can't believe you will go so low," the note read. "How many times you have dug a hole for me and my kids, only this time you have dug it so deep that I cannot come out of it. Don't ever do this to anyone. You will live to see another daylight with your twisted mind ..."

Judge Coate said that while the horror of what happened was "mercifully rare, the sentiment expressed by Mr Osborne was not. "This note bears the hallmarks of the family violence perpetrator who fails or refuses or is unable to take responsibility for his actions and indeed blames his horrendous final acts of violence against his children and himself on someone else for causing or provoking his actions." At the time of the fatal events, Mr Osborne was facing criminal charges in addition to being investigated over an alleged sexual assault against a former partner, who can only be identified as AB. AB had earlier reported concerns to Crime Stoppers regarding comments Mr Osborne had made about obtaining a firearm, and about his propensity to carry a knife. The court heard the anonymous call was made a month before the deaths.

An intervention order had been taken out by police after AB reported allegations that he had sexually assaulted her after he followed her home on March 28. Despite the order, Mr Osborne repeatedly contacted her, and was charged with four counts of breaching the intervention order and was due to appear at court to answer to the charges in July 2010. In addition to the Crime Stoppers call, Judge Coate said AB had also provided additional written information to police on April 6 about her concerns about Mr Osborne having access to guns, but such information was on a separate database that was not routinely checked by the police investigating her other complaints. "Whilst it is acknowledged that the information given by (AB) on both occasions was equivocal as to whether Mr Orborne in fact had a gun, the facts are that tragically, (AB) was right in her suspicions," Judge Coate said. Had police asked her about any concerns she had about firearms, the evidence suggested AB would have alerted police to her concerns, the coroner added.

Judge Coate said evidence obtained during the investigation from neighbours, relatives or the children's school did not identify "any obvious alerts concerning the welfare of the children". But Mr Osborne's partner at the time of his death recalled that he seemed very sad the night before the fatal events, had told her he wanted to spend his last night with her and cried a lot the following morning. But she stated that while he seemed depressed and often talked about killing himself, she did not think he would do it. Judge Coate stated the relationship between suicide and family violence was an area of growing inquiry and research. "Family violence death reviews operating within international jurisdictions have described perpetrators threatening or attempting suicide as a potential predictor for fatal outcomes," she said. "Clearly, as evidenced by the tragic and unnecessary deaths of these children, there is a need for further analysis in this area, in order to improve understandings as to the complex interaction between family violence and suicide."

In handing down her findings, Judge Coate recommended that police review the availability and accessibility of all relevant investigative databases to ensure investigating officers had "all relevant information". She also recommended police receiving family violence and sexual assault complaints make specific inquiries about the alleged perpetrators having access to, or being in possession of, firearms and other weapons. For help or information visit beyondblue.org.au, call Suicide Helpline Victoria on 1300 651 251, or Lifeline on 131 114.