A teenager being held on a slew of stolen vehicle charges has become the first person charged under NSW's so-called "posting and boasting" laws.
A man has also been charged with the fresh crime after being arrested twice in one day following the theft of luxury vehicles - including a Ferrari - from a home at Dural, in Sydney's northwest.
The 15-year-old is due to face Parramatta Children's Court on Tuesday after being denied bail on Saturday on dozens of charges.
He was the first person charged in NSW with a new performance crime offence created in March as part of a suite of changes targeting youth offenders.
The teen was also charged with 15 counts of breaking and entering, 14 offences relating to alleged vehicle thefts and breaching bail.
He was arrested on Friday along with a 17-year-old boy and an 18-year-old man.
The older boy is being held on charges of aggravated breaking, entering and stealing, and being carried in a conveyance without consent.
The trio were arrested after a Mazda SUV was stolen from Constitution Hill, in Sydney's western suburbs, before a brief pursuit at Prospect.
A police helicopter and the dog squad tracked the trio down in bushland at Northmead, near where the car was abandoned.
Days earlier, a BMW sedan and a white convertible Ferrari were allegedly stolen from Dural before being found at Doonside several hours later.
An 18-year-old man is due to face court on Wednesday over the thefts after being arrested twice on Friday.
He was initially released on conditional bail after being charged with aggravated breaking and entering and being carried in a conveyance without consent.
He was later arrested a second time and charged with an additional 12 aggravated break-and-enter offences, 10 stolen vehicle offences and the post and boast charge.
The use of the laws comes as emergency services and transport unions combine to call for police to be allowed to carry metal detectors in a bid to prevent knife crime, which they say has become widespread amongst young people.
Representatives from the NSW Police Association, Public Service Association, Health Services Union and Rail, Tram and Bus Union joined forces for the campaign on Tuesday.
Queensland Police officers have been using the wands in nightlife precincts and transport hubs since March 2023 under laws described as the "envy of other states".
The transport workers union's NSW president Craig Turner said allowing police to use metal detectors would make public transport workers and passengers safer.
"Queensland has proven that this does take knives off the streets, so we want this introduced," he said.
Australian Associated Press
