What role do physical behavior and nonverbal communication play in detecting deception?

The purpose behind this assignment is to examine two juxtaposing ethical behaviors that occur in the criminal justice system. For example, investigating officers are not only allowed but are even encouraged to lie and use deception during the investigation and interrogation process as a means to obtain to the truth and ultimately seek justice. This is an ends-justify-the-means, borderline ethical practice that shows students the pragmatic difference between deontological and ontological ethics.

Write a 1,400- to 2,100-word paper in which you discuss deception in the investigative, interrogative, and testimonial processes. Answer the following questions:

Is it ethical to lie to obtain to the truth? Do the ends justify the means?
Is there a conflict between the code of ethics and how law enforcement is really conducted?
What role do physical behavior and nonverbal communication play in detecting deception?