Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: @mikeburke91 @AP I guess. It's just heartbreaking the ease with which they can kill an innocent man and get away with it. #indignation
This tweet contains emotions: 
anger, disgust, sadness