Statement : Three persons were caught with huge arms and ammunition in the city.

Courses of Action :
I, Police should be instructed for night patrolling.
II. The three persons should be set free and their movements should be carefully watched to nab the other criminals.

Explanation:-

The police should at once be made cautious and put on high alert to prevent any untoward incident. Also, once caught, such criminals ought not to be released. They can be interrogated to detect other criminals. So, only I follows.