The firearm he possessed caused the death of his wife, Kiara Ferguson.
The 27-year-old died after she was shot with a pipe gun Winmar had made after it hit the bathroom floor of their Shepparton home on April 1, 2023.
He was previously facing a charge of manslaughter; however, it had been withdrawn by the prosecution.
The court heard Winmar had left the loaded homemade gun under a cushion inside the couch in the living room of their home they lived in with their two young daughters.
One of his daughters found the gun, and Ms Ferguson, who was pregnant with their third child, took it off her.
The court heard while Winmar was using the toilet, Ms Ferguson asked him, “what did I tell you about this?” before she “threw, lobbed or dropped” the gun.
It went off when hitting the floor, and a shot struck Ms Ferguson in the head beneath her eye, causing her death.
Justice Michael Croucher said the consequences of Winmar’s “idiotic, unsafe storage of a loaded gun” that put his family in danger would “haunt him for the rest of his days”.
He called Ms Ferguson’s death a “stroke of terrible misfortune” given all the angles and directions the shot could’ve gone.
Justice Croucher acknowledged the powerful victim impact statements that had been previously read to the court during a plea hearing, and the “loss and suffering” Ms Ferguson’s family had endured.
However, he said because Winmar hadn’t been charged over Ms Ferguson’s death directly, he couldn’t consider the impact her death has had when sentencing.
“(Her death) illustrates how unsafe the storage of the gun could be,” Justice Croucher said.
The court heard “drug-fuelled paranoia” led to Winmar to making the gun.
However, Justice Croucher said being a prohibited person, Winmar “should not have had any gun at all”, let alone a homemade one.
He said storing the “unusual and unpredictable” firearm in a hiding spot where his children could reach it was a “profoundly stupid thing to do”.
In sentencing Winmar, Justice Croucher noted his plea of guilty, exposure to drug use and violence growing up, and complex grief.
He acknowledged a manslaughter charge hanging over Winmar’s head would’ve caused “great stress and anxiety”.
He also noted the extra-curial punishment Winmar had faced, including not having any contact with his daughters since the incident, and the death of his wife.
“It’s clear he believes he is morally responsible,” Justice Croucher said.
Winmar was sentenced to three months in prison, to be followed by a 12-month community corrections order.
As part of the order, Winmar must complete 200 hours of unpaid community work, and participate in treatment and rehabilitation for drug and alcohol abuse, mental health and offender behaviour programs.