Two major (and related) barriers to listening come when the listener thinks they know what will be said and then moves forward mentally to thinking about what to do about the information that they think is about to be imparted. This can be a problem in communication in the criminal justice system just as it is in other communications scenarios.
Let us imagine that you are a probation officer. You are listening to one of your probationers. She is talking about a difficulty she is having that is making her more likely to reoffend. You have heard many similar stories in your time and so you think you know exactly what she is going to say. In your mind, you stop listening carefully to her and you start to think about how to respond to what you think she is saying. You start to think about how to fix the problem that you think she is talking about. Meanwhile, her problem is different from what you are thinking in subtle ways. You miss that due to the listening barriers.