Section 6-1(a) of the Illinois Probate Act requires that "[i]mmediately upon the death of the testator any person who has the testator's will in his possession shall file it with the clerk of the court of the proper county...." It's a felony (under section 6-1(b)) to "wilfully alter[] or destroy[] a will without the direction of the testator or wilfully secrete[] it for the period of 30 days after the death of the testator is known to him."
One question that recently arose in one of the Illinois State Bar Association's e-mail discussion groups is this: If you have a number of Wills of a deceased testator in your possession, must you file ALL of these Wills with the clerk of the court of the proper county? Or, if you believe that the most recent Will is valid and revokes all prior Wills, may you just file this most recent Will?
I am of the belief that you must file ALL Wills of a deceased testator, although you can obviously seek to have admitted to probate only the most recent one. The statute discusses "the testator's will," but doesn't define that term. Certain attorneys have suggested that they have the ability to decide which of the testator's Wills is THE testator's Will, and to file only that Will. I disagree on this point -- I think that a probate judge is the only person who can decide which Will (if any) is valid, and since filing comes before this determination, individuals in the possession of a decedent's Wills (whether attorneys or not) must file all Wills.
I will agree that the Illinois Probate Act could be clearer on this point -- a simple change to the statute would do it (maybe a reference to "any original will of the testator"?).
Note that confusion can also be avoided if the testator destroys his or her prior Will whenever he or she executes a new Will.