Los Angeles police arriving at the quiet North Hills street found a gruesome scene.
Outside a bungalow was the body of a 38-year-old man. He had been blasted with a shotgun.
Inside, the man's mother lay in a bathroom, stabbed to death.
The homeowner, Shehada Issa, 69, confessed to police that he had shot his son but explained it was in self-defense, according to detectives. Issa told police that he had heard noises inside the home and, suspecting a burglar, grabbed a shotgun only to find himself confronted by his son, Amier, who he said threatened him with a knife.
One week later, however, police say they suspect Issa fatally shot his son after killing his wife sometime during the previous 24 hours. Det. John Doerbecker said Issa's story conflicted with the crime scene evidence, saying there was no knife found near his son's body.
Meanwhile, he said, investigators have amassed evidence of animosity between Issa and his wife before her slaying. Doerbecker, who is supervising the investigation, said police were trying to find more evidence before seeking a possible murder charge against Issa in his wife's killing.
"Dad killed mom and then killed his son to cover it up," Doerbecker said, summarizing the theory investigators are working on.
The case generated national headlines over the weekend after the L.A. County district attorney's office announced that Issa had been charged with murder in his son's March 29 killing and that it was committed "because of the victim's sexual orientation." The office said Issa "threatened to kill his son on prior occasions because he was gay."
Issa's anger over his son's sexuality was a contributing factor, but not the underlying motivation for the killing, Doerbecker said.
"Generally, they didn't get along with each other," the detective said. "You might say they had problems through the years."
LAPD Det. Rich Wheeler said Issa viewed his son as a "freeloader" and wanted him to move out, but the son refused.
"He was clearly angry at his son," Wheeler said. "I think this is a case of anger and disappointment building over an extended period of time."
Deputy Dist. Atty. Emily Cole, who is handling Issa's prosecution, said her office decided there was sufficient evidence to support a hate crime allegation against Issa. She said authorities had information from Amier's siblings about previous threats their father made about Amier's sexuality.
"We have enough, obviously, to prove he killed the son, but the motive and the reasoning and everything is very much an ongoing investigation," she said.
Cole declined to provide details about the previous threats and said Issa didn't make any reference to his son's sexuality during his confession to police.
To prove the hate crime allegation, she said, prosecutors must show that Amier's sexuality was a motivating factor in the killing, not that it was the only factor.
No charges have been filed in the killing of Rabihah Issa, 68, Cole said.
Issa was being held without bail at Men's Central Jail. His arraignment is scheduled for April 11. His attorney did not return calls for comment.
The home in the 15000 block of Rayen Street was a source of turmoil since Amier moved back in with his parents, which neighbors said happened in the last two years. The LAPD said officers had been called to the home to help evict Amier, whose parents were attempting to sell the house against their son's wishes. The son had even vandalized the house, according to police.
A rambling tirade posted on Amier's Facebook page 10 days before his death said he worried that his parents, brother and sister were "literally controlling me in my sleep" and that "they tell people to rape and molest me and make it seem like I enjoy that."
"If there is a devil or evil spirit, I truly believe it manifests itself in my family," the post said.
According to court records, Amier was convicted in San Diego of assault with a deadly weapon in 2010. He had slashed his ex-boyfriend across the face with a knife, leaving him hospitalized. Amier Issa, who fled to Las Vegas during jury deliberations, was sentenced first to treatment at a state mental hospital and then to three years' probation with further mental health treatment.
The allegation that Amier's sexuality was a motive in his killing horrified many and highlighted a wider pattern of violence against lesbian, gay, bisexual and transgender people.
Gays and lesbians are among groups that are overwhelmingly affected by hate crimes, according to a report released last year by the Los Angeles County Commission on Human Relations. Sexual orientation was the primary motivating factor in one out of every four hate crimes.
The number of hate crimes motivated by sexual orientation rose by 14% to 108 between 2013 and 2014, the report said. Hate crimes targeting gay men rose 31%.
On Tuesday, a spokesman for the Los Angeles LGBT Center said allegations of violence are far from uncommon. Each day, the center has about 100 LGBT youngsters who have been abused or abandoned by their families or forced to flee because they don't feel safe at home, spokesman Jim Key said.
"Whatever the truth of this case is," he said, "the sad reality is that our LGBT youth, and people of all ages, remain targets for abuse and violence, even by family members."
Times staff writers Hailey Branson-Potts and Kate Mather contributed to this report.