A teenage gunman slaughtered 19 children and two teachers during a bloody rampage at a US school yesterday - this all we know
Salvador Ramos shot his own grandmother before heading to nearby Robb Elementary School in Uvalde, Texas, where he massacred innocent staff and children aged between nine and 11.
He had written a warning saying he was going to 'shoot an elementary school' on Facebook 15 minutes before opening fire.
The 18-year-old, clad in body armour and armed with an AR-15, began the killing spree after barricading himself inside a fourth grade classroom.
He was eventually killed by a police tactical unit.
It was the deadliest school shooting since the eerily similar Sandy Hook massacre almost a decade ago in which 20-year-old Adam Lanza first killed his mother before killing 26people.
The incident has shocked the world and seen renewed calls for gun laws to be reviewed.
Here is a timeline of what happened
Buys guns and ammo
Ramos had saved nearly £3,000 to buy two AR-15 guns - one on May 17 and the other three days later - after turning 18 last week.
On May 18, Ramos also purchased hundreds of rounds of ammunition, Texas state Senator John Whitmire revealed.
The suspect dropped a backpack with several magazines full of ammunition near the school entrance during the couse of his attack, the senator added.
Shares photos on Instagram
The teenager posted the pictures of the weapons four days ahead of his horror gun rampage.
In one photo, he tagged a woman, who has since said she had no idea who he was and tried to strike up a conversation.
During a series of messages he reveals that he has “a secret” that he wanted to share.
His last message to her is: “Ima air out”.
Facebook warnings
Ramos wrote three posts on his Facebook page warning of the attack up to 30 minutes before he opened fire at the school.
First post "I'm going to shoot my grandmother”, second post "I shot my grandmother", third post "I'm going to shoot an elementary school".
Shoots grandmother and crashes truck
On the morning of the massacre, the gunman shot his grandmother in the face following an argument at her home after he failed to graduate high school.
He had moved in with his grandparents after a number of violent rows with his drug-addicted mother, and was known to police.
Ramos' grandmother remains in hospital, fighting for her life.
The shooter crashed his car into a ditch on the way to the school.
Enters school
The shooter exchanged gunfire with border patrol officers - who had been manning a nearby post and heard shots - before making his way inside the school around 11.30am.
CNN reporter Natasha Bertrand said Ramos “was engaged by law enforcement, but made his way into the school anyway and went classroom to classroom shooting" before barricading himself into a fourth grade classroom.
The Austin American-Statesman added that Ramos “overpowered a school officer”.
School announces lockdown
At 11.43am Robb Elementary posted on Facebook that the campus was under lockdown “due to gunshots in the area”.
“The students and staff are safe in the building. The building is secure in a Lockdown Status,” said Anne Marie Espinoza, the executive director of communications and marketing for the school district.
“Your cooperation is needed at this time by not visiting the campus. As soon as the Lockdown Status is lifted you will be notified.”
School confirms active shooter
Shortly after the lockdown announcement, the school confirmed there was an active shooter.
“Law enforcement is on site," it said on Facebook.
"Your cooperation is needed at this time by not visiting the campus. As soon as more information is gathered it will be shared.
"The rest of the district is under a Secure Status."
Killed by police
Officers smashed windows around the school trying to get the children and staff out of danger before breaking into the same classroom as the gunman, according to DPS spokesman Lt Chris Olivarez.
At least one officer was injured in the confrontation as Ramos fired shots.
He was then gunned down himself.
Parents wait for hours
Families were kept away from the school for hours as staff tried to account for every student.
Well into Tuesday night, parents were slowly being reunited with their children at the Willie de Leon Civic Center.
Those who didn’t hear any news yet were asked for DNA swabs to match with the bodies that investigators were trying to identify.
Biden calls for legislation
President Joe Biden has called on Congress to pass gun safety legislation.
"We know common-sense gun laws can't and won't prevent every tragedy," he said.
"But we know they work and have a positive impact. When we passed the assault weapons ban - mass shootings went down. When the law expired - mass shootings tripled."
However, despite the crisis, politicians are expected to leave for a recess on Thursday, not returning until next week to discuss possible gun law reforms.
