When James and Margaret Richardson hear news of yet another one-punch attack, they look to one another and say: "It's happening again."
More than four years after their son Grant was killed by a single punch during a dispute with a Yangebup neighbour, the couple remain frustrated that young lives continue to be lost because of needless violence.
In the wake of Grant's death in April 2008 Mr Richardson set up a lobby group, Justice First, which provides support for victims of violence and campaigns for tougher penalties.
Mr Richardson said he hoped to make contact with Danny Green to help him promote the anti- violence message to young West Australians.
"People have got to keep their hands to themselves, it's as simple as that," he said.
"These people are cowards, because usually the person who is killed doesn't even see it coming, as was the case with my son."
Michael Stephen Barrett, then aged 21, was sentenced to 12 months jail in 2009 after he was found guilty of grievous bodily harm over the one-punch death of Mr Richardson, a 40-year-old TAFE lecturer.
Mr Richardson said his son's star "was just starting to rise" when he was killed and his death continued to affect his loved ones deeply.
He believed even tougher laws were needed to act as a deterrent.
"There's nothing to stop someone from punching someone else," he said. "The full force of the law isn't always applied. I firmly believe that when a punch is thrown in anger and a person dies, it should be classed as murder. We'll support Danny Green, by all means. Something needs to be done."