FRESNO, Calif. (KFSN) -- An 18-year-old charged with murdering his father and younger brother now faces a potential death penalty case with support from his heartbroken and confused family.
"We don't know why," his aunt said. "We knew he was worried about something. He wouldn't say what."
Robert Cotter's family still calls him Robbie and they're trying to let him know he's not alone.
And yet, they don't doubt he did what he's accused of doing and they're living with the grief.
Robert Cotter sat in court Tuesday accused of the double murder in May.
Police arrested the 18-year-old almost two months later, after initially publicly describing the incident as a murder-suicide committed by 15-year-old Brian Cotter.
Investigators say Robert told them one story, but the evidence told another.
Prosecutors charged him with the two murders and a special circumstance that puts the death penalty on the table.
Legal analyst Ralph Torres says it also gives defense attorneys more funding to investigate what led up to the shooting.
"(To) look at his history, his schooling, any kind of issues regarding mental health, any abuse there may have been," Torres said.
Family members didn't want to be identified, but agreed to talk to us.
They say Patrick Cotter, who they call Rick, had quit smoking and chewing tobacco because he appreciated living.
His younger son Brian was autistic, but coming into his own.
"He had energy," the aunt said of Brian. "He had talent. He created his own cartoon character. The first time he got behind a computer, he was like a savant. He could start piecing together films and he made his own films."
Death has become too familiar for the Cotter family lately.
The boys lost their mother a year ago and their aunt says at least six family members have died over the course of a couple years.
And now, the ones who are left say they're not abandoning Robert, no matter what he may have done.
"(We're) trying to figure out why this happened," the aunt said. "What we could've done to stop it. And I love Robbie and I hope he knows he's loved. But we just don't know why."
Cotter is due back in court next month to enter a plea. For now, he's jailed with bail set at $3 million.