modern policing - american law

this is TWO PARTS regarding policing in America and American law, please provide at least 5 references 

PART ONE - 250 words

1. Describe characteristics that define the “modern” era of policing.
2. Explain how these characteristics create a distinction between historical eras of policing.
3. Explain criteria that make modern day law enforcement effective.
4. Identify one significant event or decision from the “modern” era of policing.
   1. This item should be relatively “settled” or has been adopted or adapted to; that is, a cause and effect can be articulated. This prompt asks you to work with an event or decision for which you use present circumstances to “trace backward” a prediction.
   2. This item should contrast from the next part in that the second Part 2 asks for a wider issue that is ongoing and evolving and for which all causes, and effects are not fully understood or developed.
5. To what degree do you believe the long-term implications of that event or decision were known at the time?
6. To what degree do you think unintended consequences—positive or negative—could have been predicted?

PART TWO - 650 words

Identify a contemporary problem or case that exemplifies an emerging or evolving problem that will affect how law enforcement is applied in the future. 

• Explain how past events or circumstances inform or relate to the contemporary issue.
• If past events do not relate to the contemporary issue, explain why, and explain how the issue evolved independently.

To answer these prompts, address the following:

1. Is there a historic precedent for the issue?
2. Is the issue one that has never been resolved?
3. Explain the role law enforcement historically has played in the contemporary issue.
4. Explain the role law enforcement currently has in relation to the issue.
5. Explain how these various factors point to a precedent, decision, and/or policy that will affect law enforcement in the future.