For what it is worth.....my head doctor and I were talking about cops and there attitudes. He told me where he grew up, small town near Boston, that they used to/still do, make applicants take the MMPI 2 test
http://psychology.about.com/od/psychologicaltesting/a/mmpi.htm during the hiring process. They are looking for applicants that score poorly in certain parts of the exam, in particular Scale 4 - Psychopathic Deviate. He told me that when he lived back there and had to take this test and the reason they gave him for not hiring him was his score on this particular part of the exam.....I have always wondered if there was any truth to what he told me, but..........