Vancouver police track and arrest a suspect within 40 minutes of a violent assault in downtown Vancouver

Vancouver police say they tracked and arrested a suspect within 40 minutes of a violent assault in downtown Vancouver.

A statement from police says yesterday's assault, the latest stranger attack in the city, briefly knocked out the 18-year-old victim as she walked through the downtown core around noon.

Passers-by, including a doctor, helped the injured exchange student who was taken to hospital as a precaution, while officers canvassed businesses for video that could identify the suspect.

Using those details, police say a 26-year-old Coquitlam man wanted on a Mental Health Act warrant was spotted a short distance away and remains in custody following his arrest on assault and breach of probation charges.