A 10% reduction in crime, shows that the curfew works. Continuing to quote the 29% number just lets us know you don't understand causation versus correlation, much less causal effect. Strawman argument. If a kid is out after curfew and the cops ask for an ID, that isn't harassment, that's law enforcement. Which by the way, is the cops' job. Also, by your own admission, there was a 10% drop in crime, therefore, the cops are actually doing what you said they should be doing, by enforcing the curfew. Again, ensuring that a law is not being broken (asking young people for ID when they are out after curfew) is not harassment. If a person looks young, and they are outside after curfew, then the officer has probable cause to ask for ID (such as what's done in a Terry stop) to investigate whether the young person is breaking the law.
Read my sig below for a more concise description of how to avoid getting in trouble with the police over a curfew, as well as a simple cure for most ills that befall a person during their life.