10. Even If I Didn't Do Anything Wrong, Can It Ever Help me to Answer a Police Officer's Questions?

　　Yes. Police officers may be as interested in clearing（澄清） the innocent as in convicting the guilty. People can often clear their names as well as help the police find the real perpetrators（犯人, 兇手, 作惡者） by answering a few straightforward （簡明的；易懂的）questions. For example, assume that Wally, a possible suspect, can demonstrate that "I was at dinner with Andre" at the moment a crime was committed. Wally both removes himself as a suspect and enables the police to concentrate their efforts elsewhere.

　　Moreover, legal rights are well and good, but the "street truth" is that people often can make life easier for themselves by cooperating with police officers—so long as they don't have a good reason not to! "Contempt of cop" has resulted in the arrest and even physical injury of more than one innocent person. When innocent people who are pulled over or questioned by police officers stand on their rights too forcefully, events can sometimes get out of control rather quickly!

　　Lie Detector Tests（測謊試驗(yàn)）

　　Police officers sometimes ask suspects to take lie detector tests to "clear their names." In general, suspects should refuse to take lie detector tests. Police sometimes use the tests as tools for obtaining confessions, falsely telling suspects that they are flunking（不及格, 失?。?a test and so might as well confess. Moreover, lie detector tests are notoriously inaccurate. Innocent people often test guilty. Though lie detector test results are not usually admissible in court, even a false "guilty" result may prompt the police to make an arrest. （For more on lie detector tests, see Chapter 18, Question 36.）