This is an example of the last sign. Thinking it was someone else's fault is an excuse. After talking about the difference between excuses and reasons, you might say, "You think the reason you did not do well is your teacher's fault. Tell me how it is her fault. That is a good problem for you and me to solve."
In another situation, you say, "Let me see if I understand. Your friend Joe mouthed-off to you in the hall between English and Social Studies. This got you in a bad mood. Also, some kid was in your seat when you went into the room. This got you even more upset. You were telling him to get out of your seat when Mr. Miller came in. He got on your back; and that was too much. You said some things and he said some things and you ended up in the office. It went down hill from there and you are now on suspension. Do I have it right?"
Your youngster says, "You have that right. It was Joe's fault."
You then say, "Whose fault it was does not make much difference right now. The people at school think it was your fault. It doesn't really matter. Here is the problem. Whosever fault it was, you are the one with the problem. Let's think about the reasons why you now have a problem and figure out how you can manage and control things differently next time so you do not end up the goat. Of everything that happened, is there one thing that may not have been your best choice? Is there somewhere in there where you had a better choice if you had thought of it at the time?"
Your child's taking responsibility for his behavior can be a slow process but is necessary. The same holds for making better choices and decisions and not trying to blame others for his problems.