A lot of employers make use of online timesheet software to fire undeserving members of their team. They make sure that they can clean up the mess that their company has by removing those who are totally undeserving to be there. Well, if you are to do the same to your company, you have to be very careful. First of all, there is no guarantee that once you have caught an employee doing something bad once, it already defines him as an employee. There might be a reason for what you have just seen. If not, you might want to try it several times next time and you will see that this employee is not doing anything wrong at all.
On the other hand, there are those who are just good at first try. Yet, later on, you will realize that they are consistent in doing something bad while they are on the clock.