Screenwriting : Reading the masters helps you write dialogue by DavidandMaggie Bean

Recently, we were asked to view a piece which centered on detectives -- police work in general. The dialogue lacked authenticity. The Master of police work, in my humble opinion, is Joseph Wambaugh: http://en.wikipedia.org/wiki/Joseph_Wambaugh. By reading any of his works, you'll begin to understand this unique jargon. Can anyone think of other authors that may help screenwriters write authentically?