Los Angeles: They will make an unlikely pair: the father of a murdered college student and the father of the 22-year-old man who, in a violent rage, cut the other son down with a semi-automatic handgun.
But if criminal defence laywer Richard Martinez has his way, the two fathers at the centre of the horrific knife and gun murder of six people in Santa Barbara, California, will take on Washington's powerful pro-gun lobby.
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US community unites in grief
UC Santa Barbara community unites in grief over slain students, as Friday's violence reignites long-running gun debate as well as focus on mental health resources.
The gun control debate has been thrust back into the spotlight in US politics as the country deals with the latest in a long line of gun-related mass murders.
On what should have been a peaceful holiday long weekend in the US,Elliot Rodger, the son of Hollywood director Peter Rodger, carried out his plan to kill men and women - the men "living a better life than him" and the women who rejected him - blaming them for his frustration and loneliness.
By the time his rampage was over, three men had been stabbed to death and two women and a fourth man had been shot.
"I’ve been told that [Peter Rodger] has said he wanted to devote his life to making sure that doesn’t happen again. I share that with him," Mr Martinez told The Washington Post. "He’s a father. I’m a father. He loved his son. I love my son. His son died. My son died."
Mr Rodger has not spoken publicly, but his attorney Alan Shifman said the Rodger family would work with police and other agencies in any way necessary to stop a similar incident from happening again.
"My client's mission in life will be to try to prevent any such tragedies from ever happening again," Shifman said. "This country, this world, needs to address mental illness and the ramifications from not recognising these illnesses."
Following the mass murder, Mr Martinez has delivered a series of stinging criticisms, pointing out the failure of the US political machine to curb the proliferation of guns in American society despite a succession of similar killings in the last several decades.
"What, what has changed? Have we learned nothing? Where the hell is the leadership?" Mr Martinez said, the day after the death of his son, Christopher. "My kid died because nobody responded to what happened at Sandy Hook."
Sandy Hook Elementary School, in Newtown, Connecticut, was the site of a mass shooting in 2012 which left 27 dead.
It is one of many similar incidents of mass shooting murder in recent American history, from San Ysidro in 1984, in which 21 people were killed, to Killeen, Texas in 1991 (which left 23 dead) and Virginia Tech in Blacksburg, Virginia in 2007 (32 dead).
An established script for the aftermath of these events now follows a familiar pattern: outrage at what has taken place, an outpouring of condolences to the grieving families from American politicians but, in the face of the formidable lobbying power of the pro-gun National Rifle Association, no lasting reform.
Mr Martinez told US media he had been inundated with phone calls from members of the US Congress offering him condolences.
But, he said, "I don’t care about your sympathy. I don’t give a shit that you feel sorry for me. Get to work and do something. I’ll tell the President the same thing if he calls me."
Mr Martinez also said he did not blame police officers who, just a month before the killings, went to meet Elliot Rodger after his family raised concerns about statements he had made on social media.
A team of seven officers went to check on Elliot, but when they met with him he presented as polite and courteous. "At the time the deputies interacted with him, he was able to convince them that he was OK," Santa Barbara's Sheriff Brown said.
Mr Martinez acknowledged mental health agencies, the police department and families of people suffering mental illness were under-resourced and had few options when trying to deal with the issue.
"They don’t have the tools they need," Mr Martinez said. "I don’t have the answers, but we should ask them what they need and we should give it to them. It’s a lack of will to find solutions. That’s what I’m upset about. This is a problem that can be solved."