...
Definition: “Witnessing a signature is exactly that: you watch the signer sign the document” (NPH).
Requirements
Identity of Principal: “A notary public who witnesses or attests to a signature shall determine, from personal knowledge or satisfactory evidence of the identity of the individual, that the individual appearing before the notary public and signing the record has the identity claimed” (IC 51-105[3]).
Witness Signature Being Made: : The short form certificate of notarial act for a signature witnessing (IC 51-116[4]) states, “Signed (or attested) before me …” indicating that the Notary Public performing the signature witnessing must personally witness the principal sign the record.
“Occasionally someone will bring a document to you that has already been signed, although the preprinted form calls for you to witness the person sign the document. In situations like that, you must have the person sign the document again in your presence. It is not necessary for the signer to cross out the first signature; he or she should just sign again as close to the original signature as possible” (NPH).
...