THE father of suspected school shooter Colt Gray proudly boasted to cops about his son's first kill a year before his alleged killing spree.

After following "several anonymous tips about online threats to commit a school shooting at an unidentified location and time," Gray and his father were interviewed.

What we know so far...

An audio clip from the interview with the then 53-year-old father has since been released by cops in which he talks about his pride over his son's first kill with a hunting rifle.

Colin Gray who was arrested and charged on Thursday in relation to his son's alleged high school rampage confirmed to cops that they had weapons in the house that his son had access to.

"We do a lot of shooting we do a lot of deer hunting," he said.

"He actually shot his first deer this year."

The father then boasted about his son's kill showing cops a photograph of his son covered in deer blood.

"The picture on my phone is of him with blood on his cheeks from shooting his first deer - just the greatest day ever," Gray said.

He also acknowledged that he and his son spoke a lot about old school shootings, insisting the teenager "knows the seriousness of weapons and what they can do."

The allegations that Gray had made the online school shooting threats left his father "in shock" and "p****d off," Colin claimed.

"I'm gonna be mad as hell if he did [make the threats] and then all the guns will go away and they won't be accessible to him," he said.

The father added that he had been working to teach his son about firearms and safety and wanted to get him outside and away from video games.

Cops told Colin to "keep his firearms locked up" and advised him to keep his son away from school until the issue was resolved as there was "no probable cause for arrest" at that time.

However, it was revealed on Thursday that just months later Colin had gifted his son the AR-15-style rifle that was allegedly used in Wednesday's shooting as a Christmas gift.

Cops subsequently charged the 54-year-old with four counts of involuntary manslaughter, two counts of second-degree murder, and eight counts of cruelty to children.

At the time of the FBI investigation, Gray denied making any threats online claiming his Discord account had been hacked.

"Colt expressed concern that someone is accusing him of threatening to shoot up a school, stating that he would never say such a thing, even in a joking manner," investigators said in their report.

The FBI determined there wasn't enough evidence for an arrest at the time, but continued monitoring the teenager.

Cops have since hit back at claims that they "dropped the ball" when it came to Gray and his father, per a Sky News report.

"[We did] all we could do with what we had at the time," law enforcement said.

Gray, who is due to appear in court on Friday morning, is said to be cooperating with investigators after he surrendered to cops on Wednesday.

He "gave up and got on the ground," once authorities surrounded him, Barrow County Sheriff Judd Smith said at a press conference.

While being read his rights on school property as students and teachers were evacuated, he allegedly confessed to the crime telling cops "I did it," the Daily Mail reported.

Teachers Cristina Irimie and Richard Aspinwall, as well as students Mason Schermerhorn and Christian Angulo, were killed in the shooting.

The nine others who were injured were all hospitalized, the majority of whom have since been released.

Shots rang out at the school around 10:20 am, almost half an hour after Gray suddenly left his algebra class.

His classmate Lyela Sayarath, who was sitting next to him at the time, said there were no signs that anything was out of the ordinary, describing Gray as a "quiet and shy" boy.

However, she revealed to CNN that she "wasn't surprised" when he was identified as the suspected gunman.

"When you think of shooters and the way they act, it's usually the quiet kid and he was the one that fit that description," she said.

She told the news outlet how Gray had tried to re-enter their classroom but found the door locked.

Sayarath said a fellow student went to let him in before suddenly stopping and "backing away" after allegedly noticing had a gun.

"He turned to the classroom that would have been to my right, and he just starts to shoot, and you hear about 10 to 15 rounds back-to-back," she said.

Camille Nelms who was inside the classroom explained how everyone tried to gather in the corner as bullets flew into the room.

Other students reported hearing screams as they barricaded themselves in and hid behind desks with teachers frantically trying to keep their students safe.

The heartbreaking text messages from a student to his mum, while he was caught up in the shooting, revealed the horror they endured as the teenagers watched people die.

New panic buttons concealed within the teachers' badges saw them able to alert the cops to the shooting.

"The protocols at this school, and this system activated today, prevented this from being a much larger tragedy," Georgia Bureau of Investigation Director Chris Hosey said.

After the horror attack, Gray's family spoke out about Gray's upbringing which they claim led to the shooting.

Family members told The New York Times that the teenager had a "troubled life."

"My grandson did what he did because of the environment that he lived in," Gray's grandfather, Charles Polhamus said.

"The adults in his life let him down," his aunt, Annie Brown, added.

She added that her nephew was "actively seeking help" for his mental health, but failed to get support from those close to him.

The investigation into the shooting is ongoing and has been described as "fluid" as cops continue to look for a motive.

Gray's father is being held at the Barrow County Detention Center and was booked into jail on Thursday night.

Meanwhile, the teenager is at the Gainesville Regional Youth Detention Center and is due in court on Friday morning.