Julie : Can you give an example of negative stereotypes?
What could happen if we don't have the NYPD?
In what the NYPD is useful?
In your conclusion you shouldn't ask if our thoughts changed or not because this is not a persuasive speech.
Maybe you can conclude on the fact that NYPD is really important and that people should respect them because it's important for our safety to have people like this ;)
What references did you find?