The type of tests Zimmerman submitted to were called computer voice stress analysis. They looked for changes in his speech as he answered simple yes or no questions.
Among the questions Zimmerman answered: Did you confront the guy you shot? (No.) And were you afraid for your life when you shot the guy? (Yes.)
Video of one of the tests was released last week by Zimmerman's attorneys. But documents showing the results were only made public on Tuesday. They show the person who performed the test determined Zimmerman "told substantially the complete truth" when he was questioned on Feb. 27, the day after the killing.
Zimmerman's credibility has been damaged in recent weeks after revelations that he and his wife used code words and unusual bank transfers to try to conceal a huge amount of money from authorities.