The use of Facebook, Twitter, Vine and other social media by the three teenage suspects in the drive-by shooting murder of Australia's Chris Lane is proving to be a gold mine for Oklahoma police.
Just hours after the arrest of James Edwards, 15, Chancey Luna, 16, and Michael Jones, 17, on Friday over the killing, Duncan Police Department detectives were using a "sniffing tool" computer program to collect posts, photos and videos made by the trio on social media, a law enforcement source told AAP.
The most damning evidence appears to be against Edwards, who in one Vine video brandishes a shotgun and on his Facebook page has a photo of a handgun and wads of cash.
"I've never been this mad in my life," he wrote on Facebook just 24 hours before Mr Lane was murdered.
In another post that day he wrote: "Bang 2 drops In 2hours."
District Attorney Jason Hicks declined to comment on whether the boys were members of gangs or had affiliations, but the boys' social media accounts are being analysed by authorities for any evidence of this.
The slow, painful death Mr Lane suffered on the side of Country Club Road, Duncan, was revealed on Wednesday with the release of the 911 call by local resident Joyce Smith who was in her Toyota Corolla and saw the bloodied Australian.
"There's a young man," she tells the operator.
"He's just fell over in a ditch and he's got blood on him."
Duncan Police Chief Dan Ford said Jones told investigators the trio randomly targeted Mr Lane for execution "for the fun of it" and because they were "bored".
It's alleged they drove up behind him as he jogged along the road and Luna shot him in the back with a .22 calibre handgun.
It took seven minutes for an ambulance to get to Mr Lane, with Smith's panicked 911 call detailing how the Australian struggled to breathe, turned blue, lost consciousness and then stopped breathing before help arrived.
"If you don't hurry, he's gone," Ms Smith told the operator.
The murder has generated widespread media coverage in the US, with emotional debate over race and the nation's gun laws.
Mr Lane's girlfriend, Sarah Harper, said she "can't make sense" of the random way her boyfriend died.
"It's so surreal anyone could do something like this," she told CNN.
Ms Harper confirmed she, along with her family, will fly to Melbourne for the funeral.
A fund ( http://www.gofundme.com/3zktjc ) has been set up by Mr Lane's friends to pay for the cost of his family to fly to Oklahoma to take his body home.
The goal was $US15,000 but more than $US86,000 had been donated by more than 2900 people from around the world at 3.30pm Thursday AEST.
Edwards and Luna have been charged with first-degree murder and Jones was charged with being an accessory to murder.
