Student to Instructor to Student

I was once stationed as the head of the criminal investigation division at a small naval base. Due to a shortage of manpower, the chief of police want to temporarily move investigators into the patrol division to act as patrolmen, and, when they were need, they would revert back to being investigators until the case was resolved. I was able to convince the chief that, instead of helping the department through the manpower shortage, this change would undermine the effectiveness of both divisions.

The physical and mental characteristics required of a patrolman are opposite from those required of an investigator. There are many differences between the two, but the main difference is that a patrolman is concerned with the macro, while an investigator is concerned with the micro. The patrolman is concerned with where a gunshot came from, and finding and arresting the person who fired the gun. The investigator is concerned with how the gun was fired, who it was fired at, the kind of gun it was, etc. An investigator in patrol would probably be shot in the back while studying the hole the first bullet made. A patrolman in investigations would probably never even think about the bullet hole, but would be chasing the shooter. A good patrolman may be trained to become a good investigator, but a good investigator cannot safely be a good patrolman again.