The situation should definitely be reported to the counselor. In the meantime, the teacher can speak with the student and create a behavior plan to get the student incentives to work towards if they do not have an incidence occur in class. Some suggestions are to allow the student time on the computer to play age appropriate games.

I agree, a behavior plan is a definite must. Along, with asking the student why he/she is angry. Knowing the why will be helpful in creating a solution and finding effective strategies. It could even be home issues if the parents are as aloof as they seem from this case.

If it is not safe for the other students, something must be done immediately. First, the student should be taken to a different room, perhaps the office to complete their work. Then, the student should meet with the school counselor to discuss the problem, what may be causing it, and some possible solutions.

There are a couple of ways to approach this problem. First and foremost: Log everything! Write down the behaviors, when and how they occur. Then, call for a parent conference and show them the logs you have written to give them a better understanding of the behavior. I would also definitely use proximity control. Seat this student near you, and if possible, away from others. Have him be your "teacher helper". If the behavior is that bad where you fear for the safety of the students, submit that same log to the IEP department, and bring the student up for review. And as mentioned by others, a behavior plan is a must. Along with positive praise/rewards when he keeps his behavior in check.

If the other students are not safe, then the student should be brought into a separate room to complete their work.