It’s undoubtedly one of the most tragic and horrific things a parent can experience.
Speaking to Sunday Night, Mr Cockman believes his family would still be alive today if it wasn’t for the family court dragging out a traumatising and costly custody battle.
Mr Cockman's four young children - Kaydn, Rylan, Ayre and Taye - were asleep on his former father-in-law Peter Miles' farm with their mother, Katrina Miles, and their grandmother, Cynda Miles, when their grandfather pulled out his rifle and killed them all.
According to Mr Cockman, he was in the middle of a long and ongoing custody battle with his ex when the shooting occurred, and it had put an enormous financial strain on them all, including Mr Miles, who was supporting his daughter at the time.
"Myself and the kids and Kat, and even Peter and Cynda suffered so much through the court system," Mr Cockman told the Channel Seven program.