We may never know why Cedric Anderson barged into a San Bernardino classroom and pulled a gun on his estranged wife -- why he shot her dead in front of her students, hitting two children in the process, before turning the handgun on himself.
What we do know is what happened April 10 fits a familiar pattern of domestic violence that cannot be ignored.
By most accounts, Anderson was an outwardly cordial but secretly angry and controlling man. He had a history of abuse charges and "turned on" Karen Smith soon after they got married, when quietly she decided to pursue divorce, her mother, Irma Sykes, told the New York Daily News.
"The real Cedric came out," Sykes said, recounting how he once threatened to throw Smith out of a window.
Instead, Anderson showed up at the elementary school where Smith was a special education teacher.
He fired 10 shots. At least one of the bullets hit Jonathan Martinez, a gap-toothed, 8-year-old who died on his way to surgery. A 9-year-old student is still in the hospital.
It's a shocking and horrific case that would rock any community.
Indeed, just last month, Sacramento was reeling after police found an equally gruesome scene inside a home. Salvador Vasquez-Oliva has been charged in the killing of his wife, Angelique Vasquez, their two kids and Vasquez's 21-year-old niece.
Then, in an unrelated case a few days later, Sacramento County sheriff's deputies found 24-year-old Victoria Yasman Vasquez with a bullet in her head. A man she had been dating, Joshua Anthony Childers, has been arrested.
Most domestic violence cases aren't this extreme. Over the years, abusive relationships have evolved -- or perhaps devolved -- to include more mental, emotional, financial and even technological threats. Those are harder for outsiders to spot.
By some measures, physical violence between intimate partners is actually declining.
According to the federal Bureau of Justice Statistics, the rate dropped 67 percent between 1994 and 2012, from 9.8 per 1,000 people to 3.2 per 1,000 people.
In fact, violence committed by intimate partners declined at a faster rate than abuse by other relatives.
This is true even though more than 80 women are killed by their partners every month, according to the Violence Policy Center.
The exact reason for the decline remains a mystery, although it mirrors the broader national drop in violent crime.
In general, though, people's attitudes have changed. The federal Violence Against Women Act has gradually brought about more public awareness. People tend to see domestic abuse, particularly the kind that leaves black eyes, as a serious problem.
They watch for it and quickly condemn it.
Laws have changed, too, though there's still room for improvement.
Only about a dozen states prohibit people from possessing guns if they've been convicted of a domestic violence misdemeanor, and only five states require abusers to surrender their guns.
Studies show the presence of a firearm dramatically increases the risk that an abusive relationship will end in death.
Anderson was legally able to buy a gun because although he had been arrested multiple times on weapons charges and accused of domestic violence, he was never convicted of a crime.
All of which makes heading off the kind of murder-suicide that happened in San Bernardino all the more difficult.
But it's up to the public to provide unconditional support, not judgment, for domestic violence victims and insist on holding abusers accountable for their actions.
-- The Sacramento Bee