How come I never see any Asian Police Detectives? Is it possible for me to become a detective if I'm chinese?

Hmmmmmm..... It seems to me your father is doing nothing more than enforcing racial stereotypes. If you study and work hard, there is no reason you would not make detective. If there happen to be no Asian detectives on the Toronto force, then change that. As far as your size, a little Judo goes a loooong way, my friend.