Iowa Code § 622.27: Entries and writings of deceased person.

The entries and other writings of a person deceased, who was in a position to know the facts therein stated, made at or near the time of the transaction, are presumptive evidence of such facts, when the entry was made against the interest of the person so making it, or when made in a professional capacity or in the ordinary course of professional conduct, or when made in the performance of a duty specially enjoined by law.