A Halifax woman said someone knocked on her door Thursday, said he was a police officer and demanded she open her door. When she did, she came face to face with a masked teen with a long gun.

She closed the door on the boy — who was wearing a scarf over his face, sunglasses and a hat— and called 911. RCMP arrived on the scene, and tracked the suspect using a police dog.

Police arrested a 17-year-old boy in a wooded area about 200 metres from the residence and charged him with possession of a weapon dangerous to the public, unauthorized possession of a weapon, trespass at night and breach of probation.