One of the two men who escaped from the Banksia Hill detention centre has been arrested after police allegedly found him hiding in the roof space of a house in Nollamara overnight.
Police said about 50 to 60 youths were at an out-of-control party in Hancock Street when officers attempted to shut it down at about 1.25am.
Officers received information that the escapees Christopher Meredith, 18, and Peter Robert Garlett, 17, were at the party.
Meredith was allegedly found hiding in the roof-space and was arrested after he fell through the ceiling into the house.
He was charged with aggravated robbery whilst armed, escape lawful custody, two counts of motor vehicle theft, attempted aggravated burglary with intent and stealing.
He will appear in Armadale Magistrate's Court on August 6.
Police allege Gartlett was also at the party, but escaped police.
"Despite a comprehensive police search involving Dog Squad, Airwing, Regional Operations Group and local police, he was not located," police said.
The men had been on the run since they escaped Banksia Hill Detention Centre about 10.15am on Thursday.
It will be alleged the teenagers assaulted a construction worker at the centre before stealing a Toyota Hilux four-wheel drive and using it to smash through the metal gates to escape.
The Toyota collided with another vehicle soon after which lead the men to allegedly steal another Toyota Hilux from a shopping centre. That vehicle was also found abandoned in Camillo.
Garlett is dark-skinned, 170cm tall, with a medium build, brown hair and brown eyes.
Members of the public have been urged to immediately report any sightings to "000".