Perth: 'Awesome' bull mastiff makes citizen's arrest OUR HERO: Bull mastiff-boxer cross Bridie with proud owner Lisa Johnson and her daughter Lillian, 8. HERO: Bridie, the bull mastiff-boxer cross who perfomed a "citizen's arrest" overnight, trapping a terrified teenage burglar. A large bull mastiff has made a citizen's arrest, cornering a teenage offender who was trapped by the menacing dog in its owner's backyard in Perth's southern suburbs. A LARGE bull mastiff has made a citizen's arrest, cornering a teenage offender who was trapped by the menacing dog in its owner's backyard in Perth's southern suburbs. An "awesome dog with a beautiful nature" is how bull mastiff-boxer cross, Bridie - Perth's citizen arresting dog - is being described by her proud owners. Bridie became a hero after she confronted an 18-year-old man who jumped over her owner's back fence in the early hours of this morning, cornering him in the back patio area, standing guard at their front gate, keeping him there until police arrived to take him into custody. Bridie's owners Lisa and Glenn Johnson were awoken in their Bertram home, in Perth's south, about 1am when they heard the sound of someone attempting to open their front door. They then heard the intruder jump over their back fence, followed by loud barking and growling from three-year-old Bridie. "We heard a big thump over the side of the fence, she (Bridie) has then bailed him up, she stood at the gate barking and growling, he was holding onto the flyscreen door saying "can you let me in, get me away from your dog," Ms Johnson said. She didn't touch him, didn't bite him, didn't even nip him, she just let him know that you are going to stay here until the police get here. "My first reaction was to see if Lillian was OK, my eight-year-old daughter...immediately after that I rang triple zero, I said to the police "he is in our back yard." "They said "have you still got him there" and I said "yes the dog is not letting him go anywhere." He was petrified of her, he knew he'd stuffed up and that he got caught. Ms Johnson said her and her husband had nurtured and trained Bridie since she was a puppy and that she always got along with people and other dogs. "She is just an awesome dog with a beautiful nature...I've got a friend that is petrified of dogs but she loves Bridie," Ms Johnson added She is not snappy at other dogs either, she is just very sociable. A police spokesman joked on radio the morning that police were interested in recruiting Bridie for its specialist Dog Squad Unit. "Hopefully our officers left behind a police dog squad recruitment brochure," he said. The 18-year-old man, who had an outstanding warrant, has been charged with trespass.