Anonymous tip from Perth suburb alerted US authorities to accused Georgia school shooting suspect Colt Gray

An anonymous tip from someone in Perth’s southern suburbs about a threat online to “shoot up a middle school” last year led US authorities to the home of the teenage boy accused of being the country’s latest mass school shooter.

As investigators piece together how and why Colt Gray allegedly used a semiautomatic rifle to carry out the shooting at Apalachee High School in Winder, Georgia, a report from the Jackson County sheriff’s has revealed authorities were tipped off about the teenager and his father Colin Gray in May last year.

One of those tips came from a computer in the Perth suburb of Cockburn, The New York Times reported.

Tips sent to the FBI warned that a threat had been made in a group chat to “shoot up a middle school”.

The threats were made on the gaming social media platform Discord and as well as the computer based in Cockburn, the tips came from other devices in Palmdale and Los Angeles in California.

The authorities were then led to the doorstep of the then 13-year-old living in Jackson County, Georgia in May last year.

He and his father were interviewed about the threats posted to the Discord channel, however, both Colt and Colin denied any connection to the posts made on the account — despite the teen’s email address being linked to it.

Officers closed the case after being unable to definitively link either Gray to the Discord account.

They could not find grounds to seek the needed court order to confiscate the family’s guns and officers could not take any further action, other than to warn the boy’s middle school.

The report from the Jackson County sheriff’s office also revealed that the username on the Discord account had been written in Russian.

The translation of the Russian letters spelt out ‘Lanza’, which is the surname of the perpetrator of the 2012 massacre at Sandy Hook Elementary School in Newtown, Connecticut in which 20 students and six teachers were killed.

The pair told investigators they could not speak Russian and the teen said he had deleted old Discord accounts because he feared he could be hacked and someone could “use his information for nefarious purposes.”

The investigator noted in the report that Colt was calm and had a reserved demeanour.

After interviewing the father and son the investigators determined that they had exhausted their efforts.

“Due to the inconsistent nature of the information received by the FBI,” an investigator wrote, “the allegation that Colt or Colin is the user behind the Discord account that made the threat cannot be substantiated.”

The teenager is accused of killing two students and two teachers and wounding nine.

The 14-year-old will be charged and tried as an adult.

His father has also been charged with four counts of involuntary manslaughter, two counts of second-degree murder and eight counts of cruelty to children.