Carrie as WJR suggest a letter to the S of S requesting information on a Notary is good advice. Have done a few for people and have found that the individual was not registered with the state. Also there is plenty of information on the web providing individual state requirements. In some states a Notary is required to keep a journal of all the documents/dates they have signed. Check your state bylaws and good luck.
It also helps to get various documents that they signed, many times a Google search will bring up documents in various state registries. You can then see a time line of dates when they signed, in your letter request ask if said person was registered on those dates. Again good luck.