A white supremacist group claims it trained the suspect arrested after 17 people were shot dead at a Florida high school.
Nikolas Cruz, 19, has confessed that he “began shooting students that he saw in the hallways and on school grounds”, according to a police report released on Thursday.
It described how he took an Uber to Marjory Stoneman Douglas High School carrying a black duffel bag and a black backpack filled with loaded magazines.
The details emerged as officers said they still searching for a motive that would explain why a young man would commit the second worst school shooting in US history.
One potential lead came from the Republic of Florida, a white nationalist group, which said Cruz was a member of one of its cells and had taken part in paramilitary drills.
However, Jordan Jereb, its leader, distanced the organisation from the killings.
“He acted on his own behalf of what he just did and he’s solely responsible for what he just did,” he said.
The group wants Florida to become its own white ethno-state. On its website it claims to be “a white civil rights organisation fighting for white identitarian politics.”
Mr Jereb also told the Associated Press that Cruz had “trouble with a girl” and that he believed the timing of the attack, on Valentine's Day, was not a coincidence.
Law enforcement officers have been poring over Cruz’s social media accounts, as they search for clues.
Two Instagram accounts, which pupils at the school said belonged to the suspect, showed off a selection of firearms, including at least two shotguns and a box of rifle cartridges.
One of the accounts had a profile picture showing a bandanna-covered head wearing a Trump campaign “Make America Great Again” hat. The image has spread virally during the past 24 hours although it was not clear whether Cruz was its subject.
Taken together, the image and the Republic of Florida’s claim have heightened speculation that Cruz was motivated by far Right politics.
Scott Israel, Broward County Sheriff, said on Thursday that investigators were looking into any connection with the paramilitary group but added it was “not confirmed at this time”.
However, white supremacist ideology has been a factor in a number of shootings. Most recently, in December 2017, William Atchison killed two students at a school in New Mexico before shooting himself dead. He had previously posted on white nationalist websites including The Daily Stormer using the username ‘Future Mass Shooter’.
After carrying out the attack in Florida, the suspect is alleged to have discarded his rifle before disappearing into the crowd of students leaving the school and escaping, according to the latest version of events described by the local sheriff.
From there he headed headed to a Wal-Mart and bought a drink at a Subway restaurant before walking to a McDonald’s. He was detained about 40 minutes later.
Mr Cruz has been charged with 17 counts of premeditated murder and is being held at the county jail.
He appeared before a judge via video link wearing an orange jump suit and with his hands cuffed at his waist. He spoke only to say he understood the circumstances of his arrest.
Melissa McNeill, his court appointed public defender, described him as “a child”.
“He’s sad. He’s mournful,” she said after the brief hearing. “He is fully aware of what is going on, and he’s just a broken human being.”
Authorities are searching through his background for warning signs that may have been missed. The FBI confirmed it had been told of a comment left by a YouTube user named “Nikolas Cruz” saying, “Im going to be a professional school shooter,” but said it was unable to identify the person behind it.
Cruz was expelled last year from the school of about 3000 students and which stands in a wealthy suburb.
Pupils who knew him described a volatile teenager, whose mother died from flu last November leaving him an orphan and whose strange behaviour had led to his increasing isolation.
Thousands of people – including relatives, friends and neighbours of the victims – gathered for a candlelit vigil on Thursday night in Parkland, Florida, not far from the scene of the shooting.
The school’s senior class president read the names of all 17 people who lost their lives.
Politicians led calls for tighter regulation of firearms while the crowd chanted: “No more guns.”
Debbie Wasserman Schultz, a Democratic member of congress from Florida, said: “We must hold other people's elected officials accountable. We must make sure that they hear us.”