In a 'Naruto police officer fanfic', the potential for character development is huge. Naruto has to learn about laws, regulations, and the concept of due process which is different from the more straightforward ninja code. He also has to face the reality that not all problems can be solved with a rasengan. This internal struggle and growth, along with new storylines involving crime - solving and maintaining order in Konoha, make these fanfics really engaging. It also allows for exploration of the political and social aspects of the Naruto world that were not always in the spotlight in the original series.
The interesting part about a 'Naruto police officer fanfic' is how Naruto's ninja abilities are adapted for police work. His speed, strength, and his ability to sense things can be used in unique ways to catch criminals. Also, his relationships with other characters change. He might work closely with characters we don't usually see him interact with in the original series, like some of the civilian council members. And his ideals of justice are put to the test in a more domestic setting.