Police officers have their operation procedures very much linked to the use of radio contact between fellow member of the police force and the base of operations. This allows the up to date information to reach the policemen on where they are needed most. For example if a bank was being robbed then through radio contact the operator could inform the cars closest to the bank in order to reduce the amount of time it takes to reach the scene of the crime. This aids in reducing the chances of the criminal being caught and help given in civilians who just happen to be in the wrong place at the wrong time.
When in pursuit of a criminal that is in a vehicle the radio allows a coordinated pursuit to occur that heavily increase the chances of the criminal driver being stopped and caught. What usually happens is several police cars follow different surrounding routes in the direction the car criminal is driving in and then attempting to block him in on a road up ahead. This can only be done if the radio contact between the policemen is used in order to tell each other where exactly the criminal is at all times.
If a policeman happens to walk into a shop where a robber is in the act of the crime then radio contact with the base could be used in order to get backup in as quickly as a couple of minutes. This is a huge advantage as it allows the criminal to be defeated by the sheer numbers of officers after him.