The 14-year-old boy charged with fatally shooting two students and two teachers with an assault-style rifle at a high school in Georgia on Wednesday had previously been interviewed by investigators, with his father insisting the teenager did not have unsupervised access to the family’s guns.

The small city of Winder is in deep shock and mourning over the shooting at Apalachee high school, about 50 miles from Atlanta, as the victims who died were named.

The teenager has been charged as an adult in the deaths of the school students Mason Schermerhorn and Christian Angulo, both 14, and educators Richard Aspinwall, 39, and Christina Irimie, 53, the director of the Georgia bureau of investigation, Chris Hosey, said.

At least nine other people – eight students and one teacher at the school – were taken to hospitals with injuries and all were expected to survive, the Barrow county sheriff, Jud Smith, said.

More than a year ago, tips about online posts threatening a school shooting led Georgia police to interview Colt Gray, then 13, but investigators did not have enough evidence for an arrest. On Wednesday, Gray was accused of opening fire at his school and on Thursday he was to be taken to a regional youth detention facility, after surrendering to the authorities when he was challenged during the shooting.

Armed with an assault-style rifle, the teenager allegedly turned the gun on students in a hallway at the school when classmates refused to open a locked door to their classroom, which he had left and then tried to get back into during an algebra lesson, a classmate, Lyela Sayarath, said.

The FBI said that Gray and family had been interviewed last year.

“The father stated he had hunting guns in the house, but the subject did not have unsupervised access to them. The subject denied making the threats online. Jackson county alerted local schools for continued monitoring of the subject,” the FBI said in a statement.

Hours after the shooting, state and federal law enforcement raided the Gray family home. Investigators told Fox 5 in Atlanta that they were looking for weapons, as well as digital devices that could give clues as to the timeline of what happened.

Joe Biden and Kamala Harris have separately condemned the killings. The US president called on Congress to pass tighter new gun laws, in a statement issued by the White House, and the vice-president and Democratic party nominee for president in the November election called it a “senseless tragedy” and called for “an end to this epidemic of gun violence”.

Harris added: “It doesn’t have to be this way.”

Students at the school spoke of their terror at hearing gunshots and the sound of screaming outside their classrooms. Alexsandra Romero told the Atlanta Journal-Constitution said she initially assumed it was a drill when another student burst into her classroom shouting for everyone to take cover.

“I can just remember my hands were shaking. I felt bad because everybody was crying, everybody was trying to find their siblings,” she said.

It was the 385th mass shooting in the US this year, according to the Gun Violence Archive. It was the eighth school shooting of the new school year, which has barely begun, ABC’s Good Morning America show reported on Thursday.

Biden, in a statement on Wednesday, said the shooting was “another horrific reminder of how gun violence continues to tear our communities apart”, and called on Republicans in Congress to work with Democrats and pass “commonsense gun safety legislation” including a ban on assault weapons and high-capacity magazines and universal background checks for gun buyers.

“These measures will not bring those who were tragically killed today back, but it will help prevent more tragic gun violence from ripping more families apart,” the president said.

Fundraising pages have been set up to help the families of the four victims cover funeral costs. Lisette Angulo, who identified herself as Christian Angulo’s oldest sister, described her 14-year-old brother on the site as “a very good kid and very sweet and so caring He was so loved by many … We are truly heartbroken.”

The other student who was killed, Schermerhorn, was described by friends of the family who talked to the New York Times as a lighthearted teenager who enjoyed “reading, telling jokes, playing video games and visiting Walt Disney World”.

Both the teachers who were killed, Aspinwall and Irimie, taught mathematics. Aspinwall also coached football, having been hired by the school as defensive coordinator before the 2023 season.

People in Winder, a city of just 18,000, gathered in a park for a prayer vigil later on Wednesday night. Some leaned on each other or bowed their heads in prayer, while others lit candles to honor the dead.

“We are all hurting. Because when something affects one of us it affects us all,” said Power Evans, a city councilmember who addressed the gathering. “I know that here tonight, all of are going to come together. We’re going to love on one another … We’re all family. We’re all neighbors.”

The US has seen hundreds of shootings inside schools and colleges in the past two decades.

The Associated Press contributed reporting