It was a gruesome incident by any measure.
A group of Chicago teens bound and attacked a mentally disabled teen and broadcast the violence on Facebook for the public to see.
But then six words the black attackers said as they assaulted their white victim changed the nature of things, sending what would normally be a local crime investigation in one of the country's most violence-plagued cities into the national fray over a combustible mix of race, social media and the presidential election.
"F— Donald Trump" and "F— white people."
Police charged four teens on Thursday with hate crime, kidnapping, battery and unlawful restraint after investigating the Facebook Live video that showed them attacking and taunting the mentally disabled 18-year-old, punching him while yelling obscenities against the boy's race and Trump.
The 30-minute video, put up on Tuesday and later removed, has spread widely online. It shows the victim sitting in a corner with his wrists bound and mouth taped shut as his attackers laugh at him. At one point they attempt to cut off a patch of his hair as his scalp bleeds.
The victim was treated at a hospital for unspecified injuries and was reported to be home with his family.
Police say they think the victim, whose parents had earlier reported him as missing, was attacked because of his disability, not because of his race.
Yet the references to white people and the president-elect have set off a storm of animosity and finger-pointing.
White nationalists have spread the clip online via Twitter, using the hashtag #BLMkidnapping to blame the Black Lives Matter movement for the crime, although there is no evidence of a connection. Conservative commentators have taken up the hashtag and complained that crimes against white Americans receive less attention from police and the news media than crimes against members of other races.
Civil rights groups that have tracked hate incidents since the election that have invoked the president-elect's name have publicly weighed in, while Trump supporters have pointed to the attack as evidence of what they say are growing threats of violence against them.
"This comes at a heated time, when different political sides are trying to gain currency, which misses the point. Whether it's [the Ku Klux] Klan and violence from them or violence like in this case, the actual facts of the situation can get lost," said Brian Levin, a professor at Cal State San Bernardino who tracks hate crimes. "Anytime something is captured on video, especially if it involves social media, it can become volatile and people become concerned just with what circulates in their social media world."
In an interview with a Chicago television station, President Obama called the attack "despicable," but said he didn't believe there had been an increase in racial animosity in the country — just a greater awareness of it because of cellphones and the Internet.
"What we have seen as surfacing, I think, are a lot of problems that have been there a long time," Obama told WBBM-TV Channel 2.
Civil rights groups, accustomed to monitoring crimes against racial and religious minorities as well as against immigrants and LGBT individuals, said the attack and attention to it took them by surprise.
"The crime is shocking. I'm glad the authorities have moved so quickly," said Southern Poverty Law Center President Richard Cohen. Among the nearly 1,000 hate-related incidents the Montgomery, Ala.-based organization has tracked since the presidential election — many of which invoked Trump's name and targeted Muslims, blacks, Hispanics or immigrants — Cohen said the organization also found 26 reports of incidents targeted against Trump supporters.
It's unclear whether the Chicago victim, whose name has not been released, had shown support for Trump.
It's also unclear what broader views the attackers have against white people or how they might have expressed them before the attack.
Police reported that at least one of the suspects, 18-year-old Jordan Hill, attended school with the victim.
Officials said the two met on Saturday at a McDonald's outside the city for a sleepover at Hill's. Instead, officials said, they traveled to visit friends on the city's West Side in a van Hill had stolen and passed off as his own. On Tuesday, they ended up at the apartment where two of the other suspects lived and where the attack occurred after what police described as a "play fight" that got out of hand. The victim later escaped, and police found him wandering the streets.
"I took the anti-Trump rhetoric as a synonym for anti-white rhetoric," said Cohen, who said he "would not rule out race" — as opposed to only disability — as a factor in the attack. Cohen added that attacks against people over their disabilities are typically low — just 1.2% of hate crimes in 2015, according to the latest FBI statistics.
Richard Spencer, a white supremacist who runs a group called the National Policy Institute and has received widespread media coverage for his vocal support of Trump, attempted to use the Chicago incident to show his view that whites are being attacked by Black Lives Matter activists.
"This isn't even the first instance of terrorism against whites by anti-Trump #blacklivesmatter supporters in Chicago," he tweeted Wednesday.
"Remember the #blmkidnapping every time some journalist lies about my white advocacy organization and calls it a hate group," he tweeted the same day.
Anti-white hate crimes are among the least common of attacks tracked by the FBI. Slightly more than 59.2% of hate crimes in the country in 2015 had a racial motivation. Of those 4,216 racially motivated hate crimes, more than half were against blacks, while 18.7% of victims were targeted due to anti-white bias.
"The FBI only tracks reported crimes that have been investigated, so it's hard to say with any broad certainty whether hate crimes against whites have gone up or down. But I would say the level of hate in our country — and certainly after the election— has gone up over the last decade. We're becoming more polarized and social media allows us to amplify it," Cohen said.
Black activists such as those in the Chicago Black Lives Matter chapter have also used social media to fight back against accusations that crimes this week were related to their efforts.
"We've stated time and time again, that we're against all types of harm and violence perpetrated and we've never condoned it. So this is absolutely perplexing and twisted that people are associating this atrocity with this organization and movement," the group said Wednesday in a Facebook post.
"If you really cared about the victim then you'd be advocating for their care and treatment for trauma. That's what we want. We want centers for healing and mental health care," the statement said. "However, some people are more concerned with attacking us and they don't see how demented that is."
William Lee of the Chicago Tribune contributed to this report.
5:40 p.m.: Updated with additional information about the sequence of events.
4:30 p.m.: Updates on the victim's release from the hospital and President Obama's reaction.