A report of an apparent robbery sent officers to a home at about 9 p.m. Friday, Handfield said. A man who had fled the home told police that his sister's ex-boyfriend knocked on the door and then took his father, mother and younger brother hostage at gunpoint.
A SWAT team was called in and evacuated six to 10 neighboring homes while a crisis negotiator talked to the gunman, Handfield said.
During the standoff, the gunman also allowed hostages to speak to the negotiator, Handfield said.
Sometime after that, however, he apparently shot and killed the father, and wounded the mother and son, Handfield said.
The man finally surrendered, sending the wounded woman out in front of him, Handfield said.
The body of De Ngoc Le, 60, was found in the home along with the wounded man, police said.
Gibson's father, Alwyn Gibson, told the Orange County Register on Saturday that his son seemed to be mentally unstable.
"Something was not right with him," the father said in a phone call from his Texas home. "He blamed other people for his problems, like his girlfriend, his brother and his mother."
He said his son had lived with a girlfriend in Southern California for several years but moved back to Texas about four months ago.
He got a job as a prison guard with the Texas Department of Corrections but quit because of "inconsistencies with attendance," his father said.
Officers at the scene did not hear the shots because the man used a small-caliber handgun with a homemade silencer, which was found in the home, Handfield said.
The mother was hospitalized in good condition with a gunshot wound to the upper arm and her son was in stable but serious condition, Handfield said.
Their identities were not immediately released.
Family members told police that Gibson suffered from "mental instability," Handfield said.
Gibson and his girlfriend broke up in August and "he was distraught over relationship issues," Handfield said. "The family has had prior episodes with him."
Gibson's former girlfriend did not live in the home and was not there at the time of the attack, Handfield said.
Gibson grew up in Southern California and was a graduate of Fallbrook High School in San Diego County, his father said.
The father said his son had twice driven back to California in recent months to see his ex-girlfriend.
"I got the impression that he was trying to work things out," he said.
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