The FBI has confirmed that it was warned about the teenager who allegedly carried out a mass shooting at his former school in Florida.
Nikolas Cruz, who has been charged with 17 counts of premeditated murder, reportedly left a comment on a YouTube video last year stating: “I’m going to be a professional school shooter.”
A user alerted authorities to the post.
Teachers were also warned about Mr Cruz, who was not allowed on campus with a backpack, US media report.
The FBI said it had investigated the YouTube comment but had been unable to fully identify the person who posted it.
Seventeen people were killed and many more were injured in the attack at Marjory Stoneman Douglas High School in Parkland, Florida. Several people are in a critical condition.
It is the deadliest shooting at a US school since 2012.
What were the warnings?
After seeing a comment on a YouTube post last year by Mr Cruz, 19, user Ben Bennight contacted the FBI with his concerns. He said he spoke to representatives there for about 20 minutes.
Mr Bennight said that the FBI had contacted him again following the school shooting in Parkland.
The FBI confirmed on Thursday that they were made aware of the comment, adding that they had conducted “checks” but were unable to identify the person behind it.
Meanwhile, maths teacher Jim Gard told the Miami Herald that school authorities had emailed teachers about Mr Cruz’s behaviour.
“We were told last year that he wasn’t allowed on campus with a backpack on him,” Mr Gard told the Miami Herald.
“There were problems with him last year threatening students, and I guess he was asked to leave campus.”
School officials have not disclosed why Mr Cruz was expelled from the school.
Former schoolmate Joshua Charo said Mr Cruz had been found with bullets in his backpack.
“I can’t say I was shocked,” Mr Charo said.
“He seemed like the kind of kid who would do something like this.”
Some other students echoed that opinion when interviewed.
“Everyone predicted it,” one told WFOR-TV.
But police said they were not warned of any possible attack by Mr Cruz.
Superintendent Robert Runcie told reporters: “We received no warnings.”
Who were the victims?
Details of the 17 victims are emerging as they are identified.
The school’s assistant football coach Aaron Feis was taken to hospital after jumping in front of students to shield them from bullets. His team tweeted that he had “died a hero”.
The family of student Jaime Guttenberg confirmed her death in a Facebook post on Thursday, referring to the 17-year-old as an “awesome young girl” and updating her page on the social media site to create a memorial for her.
Her cousin Marc Pollack posted a tribute, writing: “My heart is broken from the loss of this awesome young girl and the pain that our entire family is enduring.”
Ms Guttenberg’s parents earlier said that her brother Jesse had escaped unharmed.
Another student, Alyssa Alhadeff, has been identified by her family as a victim of Wednesday’s shooting. In messages shared on social media, her cousin confirmed that she had been found dead.
What happened at the school?
Reports suggest that a fire alarm at Marjory Stoneman Douglas High School in Parkland, Florida, was deliberately set off at 14:30 local time (19:30 GMT).
The alarm caused some students and staff to leave their classrooms.
Witnesses said that the gunman was deploying smoke grenades and wearing a gas mask.
Students told US media they hid under desks or in store cupboards or barricaded doors as loud shots rang out.
It is with Great sadness that our Football Family has learned about the death of Aaron Feis. He was our Assistant Football Coach and security guard. He selflessly shielded students from the shooter when he was shot. He died a hero and he will forever be in our hearts and memories
