It all depends on the terms of your own progressive discipline policies and procedures. If the employee is in a union, be sure to follow the policies and procedures set out in the collective agreement.
I hope you have a written policy laying out the various steps, e.g., warning, written warning, unpaid suspension, etc. If not, you need to create one. In the meantime, assuming you don’t have written policies and this isn’t a union case, try to apply the same principles and procedures you have when dealing with similar matters in the past. Hopefully, the suspension will be consistent with how you’ve handled those matters.