After a black man was shot seven times in the back by a police officer in Kenosha, Wisconsin, on Sunday, 23 August, people angry about police violence began protesting.
On the third night of demonstrations, a 17-year-old boy allegedly fired on protesters with an assault rifle, killing two and seriously injuring a third.
On Wednesday he was arrested at his mother’s home. He now faces a first-degree murder charge.
Videos indicate he spent hours on Tuesday patrolling the streets before turning his weapon on demonstrators. He told journalists it was “his job” to guard buildings and even offer medical assistance to protestors.
Here’s what we know about the teenager, his connections to a Donald Trump rally and membership of a Facebook group reported for inciting violence.
Who is he?
Details are still emerging about Kyle Rittenhouse, but his social media profiles show a fascination with police dating back several years.
A Facebook photo of him was framed with the “Blue Lives Matter” logo – a staunchly pro-police movement that often clashes with Black Lives Matter supporters.
Several of his posts honoured police officers killed on duty, and he also posted pictures of himself wearing full police uniform. He is a former member of a local police cadet programme, Grayslake Police Department says.
Guns are another of his passions. Photos of the suspect show him posing with weapons, practicing target shooting and assembling an assault rifle.
In an interview on Tuesday night before the shootings, he echoes police language when telling a journalist why he is armed.
“Part of my job also is to protect people. If someone is hurt, I’m running into harm’s way,” he says.
Later a video appears to show him shooting a man in the head. He then appears to be chased by a crowd before falling to the ground, and firing his gun at them.
He then approaches police vans with his arms in the air. A by-stander shouts “that dude just shot them”, but the vehicles pass by to attend the injured protesters.
Police arrested him in Antioch, Illinois, which is about 15 miles (24km) from Kenosha.
Who were the victims?
A 26-year-old from Silver Lake, Wisconsin, and a 36-year-old from Kenosha were both killed. A 26-year-old is expected to recover from injuries. Police have not named them.
They were on Kenosha’s streets on a tense night that saw protesters clash with police and armed vigilantes.
Demonstrators are angry about another police shooting of a black American weeks after the US was engulfed by a huge movement calling for an end to racism and police brutality.
Jacob Blake, 29, was shot seven times in the back by officer Rusten Sheskey while getting into his car with his children on Sunday. His lawyer says it will be a “miracle” if he walks again.
Limited law enforcement in Kenosha has led to individuals and groups taking the law into their own hands during the unrest, a spokesman for the Wisconsin Professional Police Association told the BBC.
Videos from Tuesday show armed civilians in military clothes congregating outside buildings in the city.
What are the alleged shooter’s connections to Donald Trump?
The suspect’s social media accounts suggest he was an ardent supporter of President Donald Trump.
Video shows him cheering in the front row of an Iowa rally for the president’s re-election campaign. He also posted video from the event on his TikTok account.
His Instagram profile bio read “Trump 2020”.
A spokesperson for Mr Trump told BuzzFeed News that the teenager had “nothing to do with our campaign”.
“President Trump has repeatedly and consistently condemned all forms of violence and believes we must protect all Americans from chaos and lawlessness […] We fully support our fantastic law enforcement for their swift action in this case,” they added.
What’s the connection to a militia Facebook group?
Before the protests, a Facebook group called Kenosha Guard issued a “call to arms” to its members.
Members reportedly discussed what weapons and what type of damage to inflict on protesters’ cars.
Several users warned Facebook that the group was inciting violence but were told the post did not violate the platform’s standards, reports the Verve.
It was eventually removed after the shootings on Tuesday night.
“At this time, we have not found evidence on Facebook that suggests the shooter followed the Kenosha Guard page or that he was invited on the event page they organized,” Facebook told the Verve.
What’s the reaction?
More than 200 FBI agents are being sent to Kenosha to try to bring order to the city, and the White House says 2,000 National Guard members are available to go.
Right-wing Fox News presenter Tucker Carlson sparked uproar on Wednesday when he appeared to justify the shootings.
“How shocked are we that 17-year-olds with rifles decided they had to maintain order when no one else would?” he said on his TV show.
He said Kenosha had descended into “anarchy” after being “abandoned” by authorities.
He was swiftly condemned on social media.
“An innocent black guy is killed by police and Tucker Carlson calls him a thug. A guilty white guy murders two people and Tucker Carlson calls him a patriot,” tweeted CNN commentator Keith Boykins.
Meanwhile a viral rumour claiming that protesters fired a Molotov cocktail at the alleged shooter has been debunked.
Some claimed the video suggested the suspect was acting in self-defence, but other footage from the scene showed that in fact the protester threw a bag.