Indiana Code Title 29. Probate § 29-1-7-9

Sec. 9. Before a written will shall be admitted to probate, the will shall be proved by one (1) or more of the subscribing witnesses, or if all of them are dead, out of the state, or have become incapacitated for any reason since attesting the will, then the will shall be admitted to probate upon proof of the handwriting of the testator or of one (1) of the subscribing witnesses.