I have no information on who conducted the interview or when, but I'm guessing about 1995 from a date at the beginning of the tape. It appears it was done in Bishop, California by something he stated during the interview.
As I said, this is raw and uncut footage - the first 18 minutes are photographs of the raid....you can skip forward to 18:19 to watch the actual interview. Unfortunately it cuts off at 54 minutes, just before the raid-- that's all there is...but all in all I found it interesting.....enjoy...
You can read more about Officer Pursell and the Barker Ranch Raid here:
http://www.lamag.com/features/2009/07/01/manson-an-oral-history1/page/4