Classify the emotions found in the tweet "@mikeburke91 @AP I guess. It's just heartbreaking the ease with which they can kill an innocent man and get away with it.". Select from the following: anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust. If the tweet is emotionless, reply "neutral or no emotion".
anger, disgust, pessimism, sadness