The two teens will remain behind bars after being refused bail in connection with the stabbing death of the man in a public square.
The man in his 30s, not yet formally identified, died on Cleeve Close in Mount Druitt, western Sydney, on Friday night after initially being stabbed in Dawson Mall.
NSW Police Superintendent Darrin Batchelor said a family had lost a father, son and brother.
"In my career, my 30-year career of policing, I find this absolutely senseless," he told reporters on Monday.
"(He) was going home from work, going about his business, stopped to talk to some family friends - he's now dead.
"I have no doubt the impact on the community and the victim's family will go on and on for years."
Police found the man suffering stab wounds to his torso, behind Westfield Mt Druitt about 9pm.
He died before paramedics could arrive.
Two teens, aged 13 and 16, faced a childrens court on Monday, the younger teen on a charge of murder.
After the stabbing, two teens were allegedly spotted on CCTV at Mt Druitt train station, where the 13-year-old was carrying a jumper he had previously been wearing.
The sleeve of the jumper had blood from the stabbing, a prosecutor told the childrens court.
After allegedly giving up his jumper to hide the blood, the older teen allegedly provided a second set of clothes later in the evening to help disguise the younger boy.
He has been charged with being an accessory after the fact to murder and sought release to bail on Monday.
"He hasn't involved himself in any of the assault," Ben Willcox said.
"When the police arrest him, he goes with them willingly.
"He hasn't previously been found guilty of any (violent) offence."
But Judge Marguerite Vassall found the 16-year-old posed an unacceptable risk of committing a further serious offence, given he had been on a good behaviour bond.
She refused bail.
The younger teen did not apply for bail.
The pair were arrested on Sunday night after a public appeal for information over the weekend.
Police are looking for about a dozen people in the Dawson Mall area when the man was fatally wounded.
CCTV footage, published by media outlets and allegedly depicting the incident, showed a group of several males walking along a street before a man threw a punch and was attacked by three others in retaliation.Â
The two teens will next appear in court on October 23 for another bail application.
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