You will need to go to the Harris County Website and look for the HCAD link (Harris County Appraisal District). Dig around there and you should be able to find the deed history of the property. REALTORS are not suppose to divulge this information, but it is mostly public record and Harris County has a great website.
You can find this information via the Auditor for the county in which the property is located. If you want this service hired, chose a title company local to the property, and pay them to do a title search.