So you think juries are not capricious?
Most of the time juries act in good faith, based on their ability to understand the evidence, the law, and act within His or Her Honor's instructions.
Still, people can be swayed by their unrelated life experiences or their emotions played upon by a skilled manipulator.
"No man's life, liberty or property are safe as long as congress court in in session" ~ Gideon J. Tucker, paraphrased...