Checking the authenticity of Documents is the job of professionals. While lawyers can be experienced in this matter, generally the title company is the one who needs to make sure that the information is correct, as they are the ones who provide title insurance.
Firstly you should check with other realtors and other buyers what their experience has been. Secondly, you should ask your questions to the person giving you the documents. Thirdly, you should consult with an attorney. It is better if you already have a good idea of the issue at stake before you speak to the attorney.
I would recommend you hire a lawyer to verify the documents that you have obtained. Keep in mind that you want to be protected from fraud so seeking a legal consult will help you avoid that scenario. Good Luck!