If you have to fire an employee on the spot and its involuntary, do you still have to give the employee their final pay check right then and there as stated in ca labor code 201 202? I understand the 72 hour law, or if you are planning to terminate someone to have the check ready. But if its unexpected, is the company obligated to give their final pay check on the spot?

California, yes. Doesn't make any difference whether it was a planned discharge or not.

What if the employee turns violent and aggresive to do a counseling session. Still need his check on the spot?

The law doesn't come with qualifications. It doesn't give you an out from following the law if the employee behaves poorly. Yes, still check immediately.

That doesn't mean you have to have it in your hand when you confront him, but he has to have it before he leaves for the day.

Yes. You need to have some sort of procedure in place to do an immediate check, or you need to suspend the employee until you can get their check ready, rather than firing them immediately.

A suspension would give you until the next pay period.

When an employee is dismissed from work and not given a definite time within the next pay period in which to return to work, it is a termination as far as immediate payment of wages is concerned. If the suspension is paid, obviously, it can last indefinately.
Thanks mtracy
http://www.laborlawtalk.com/showthread.php?t=88592

If it were a paid suspension, it appears it would buy you time, since the employee is still in a paid status. If it's an indefinite unpaid suspension, the cite you quoted clearly (at least, to me) states it's a termination.

When I managed the payroll function for a large company in California, we had a couple of ways to deal with this. You don't need to "suspend" them theoretically. Just tell them their services are no longer needed today and to come back at the regular scheduled time tomorrow; then give them their check at that time (of course, you'll have to include reporting pay as appropriate). Or, since we were a chain of restaurants, we could calculate the final pay and fax the breakdown to the restaurant. They would give the employee a copy (to serve as the required pay stub) and pay them the net in cash from the register. Just a couple of thoughts.

Sorry, I was not clear. I was not thinking of an indefinate suspension, but rather suspending them until you could have their check ready. Three days is a very common time used. As Patty says, you will need to pay the reporting time.