RTE.
I am not familiar with OK. public records laws. You might try doing a search in the tax assesor/ property appraisers records to find the property owner of record. You could also search the Public records of the courthouse to find if there is any civil or non-felony criminal records for Hinrichs. Public records should also show if he was involved in any property transactions.
It would also interest me to know if Hinrichs was a joiner. Did he try out different groups to find one that met his philosophy. You would expect to find this behavior in someone who was frustrated and looking for answers.
I have done 2/3rds of that suggestion and "nada". There is one more thing I haven't done yet and will report findings when I have.