Police said Leo Rubio, his wife and their 10-year-old son arrived home Saturday night and found Ruben Arzu, 22, sitting naked on their porch bench.
A physical confrontation then occurred that left Rubio with a broken jaw and his wife with a fractured skull.
"I'm truly, truly sorry for the couple that got hurt," said Arzu's mother, Mariela Arzu. "We were trying to avoid that and nobody heard us or heard his cry."
Arzu said her son was not under the influence of drugs at the time. She said she had a conversation with him that morning where he said he needed help.
"He started wanting to cry and he says, 'Mom, I need help,' and I could see it in his eyes that he was screaming for help," Arzu said.
Later that night, Arzu said her son left home with his girlfriend on a walk. They talked for a while, but his girlfriend said he became agitated.
"He totally was a different person," said Arzu's girlfriend, Denise Mainez. "It was like something happened within him I can't explain."
At that point, Mainez said she left with their 1-year-old daughter.
The family got a knock on the door from police not long after, who told them Arzu had attacked two people.
"It's just hard to believe seeing what he did, taking his clothes off and stuff," Mainez said.
The family showed Eyewitness News documents showing that in the 8th grade, Arzu could only comprehend things at a 3rd or 4th grade level.
Another document from Social Security showed that he receives benefits as a disabled person.
The family says he's not a bodybuilder, but he did like to work out at his home.
Arzu is behind bars on attempted murder charges.
The husband and wife were released from a hospital Tuesday.