In this extract from Law and Order: Special Victims Unit, we get to see a great example of quality interpretation. I do not know American Sign Language so I can’t comment on the accuracy of the interpretation, I will instead focus on the police officer’s conduct and ethics.
Despite being in her police uniform, the interpreter does not act as a police officer but solely as interpreter. She does not react to the suspect’s answers, even when he incriminates himself. Conversely, she does not take any side-bars with the interrogating officers.
In this interrogation, the interrogated suspect has no reason to suspect a bias from the interpreting officer, which ends up leading to a less inhibited interrogation, comparable to an interrogation without an interpreter present.
It is safe to assume that the police officer serving as interpreter would help the interrogating officers if given the chance. She simply realized the best way she could help was to give accurate and objective interpretation to overcome and minimize the difficulty of having a language barrier instead of trying to use it to trick or trap the person being interrogated.