Please analyze 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." and classify its emotional content. Choose from the following emotions: anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust. If no emotions are detected, respond with "neutral or no emotion".
anger, disgust, pessimism, sadness