YOUTHS walking home from a high school post-ball party in Wangara were the targets of violent alleged robberies.
Joondalup detectives this week charged three teenagers accused of assaulting and stealing from the victims in separate incidents on February 11.
In the first instance, four youths were walking east on Berriman Drive between 3.30am and 4am when they noticed three males following them.
One of the victims stopped to talk to the trio, but allegedly found himself in danger.
The trio is accused of threatening the boy then stealing his wallet, phone and gold chain before punching him in the face.
In the second alleged robbery, two teenagers were walking on Wanneroo Road towards Windsor Road when they noticed three males at a business on the other side of the road about 4am.
Two of the males allegedly threatened the victims before stealing their phones, wallets and cash.
Police charged a 17-year-old Wellard boy and 19-year-old Pearsall man with aggravated armed robbery and aggravated robbery.
They also charged a 15-year-old East Victoria Park boy with aggravated armed robbery.