On Sunday night, under cover of darkness, a homeless man was beaten to death as he slept outside a Queensland community centre.
David Collin, 53, was found with horrific head injuries at about 8.30am on Monday by an employee who immediately called police.
His killer, or killers, launched what detectives called a "violent", "cowardly" and "unprovoked" attack on Mr Collin, striking when he was at his most vulnerable — asleep inside his sleeping bag.
Sickened detectives have vowed to hunt down whoever is responsible and say six people captured on CCTV in the vicinity over a period of around 12 hours may hold vital information that could help solve the crime, news.com.au reports.
Sunshine Coast Criminal Investigation Branch Detective Senior Sergeant Daren Edwards said Mr Collin may have stood out to others because he transported his possessions in a carry bag with wheels.
He said investigators were trying to establish a timeline for the murder, focusing on a window of approximately 12 hours during which the attack was believed to have been carried out.
In that time, six people were seen near the crime scene. Police want the passers-by, who were caught on CCTV, to come forward because they may hold vital information on the killer.
"Between 6pm on Sunday evening to daylight on Monday morning, six people can be seen walking in the vicinity of where Mr Collin slept that night," Sgt Edwards said.
"There are a couple of people on pushbikes and a few walking who we would like to identify and come forward."
"Additionally, we would appeal to anyone who may have seen anything suspicious around the Millwell Road Community Centre on Sunday night or early on Monday morning to contact police.
"This appears to have been a very cowardly attack on a vulnerable person, and we will continue to pursue all lines of inquiries to find whoever is responsible."
A witness told the Sunshine Coast Daily the body was found in a sleeping bag and blood could be seen around the man's head.
Police are appealing for anyone with information who was in the area, including those who may have dashcam footage, to contact Policelink on 131 444.
Information can also be provided anonymously to CrimeStoppers on 1800 333 000.