Crime Patrol

When a gang of robbers can continue burglary in four addresses one after the other in a the Salt Lake area of Kolkata and then allegedly rape a minor girl, with the police in dark, one can safely conclude that the city is in the grip of crime. Leaving alone private professional security measures and the inmates of the buildings affected, how come the police allow such crimes to continue unabated in the city? Also, the common citizens themselves should be doing more to prevent such crimes, especially when both public and private security measures are proving unreliable.