Rafferty and Llewellyn mystery by Geraldine Evans and was part of a "boxed" set for Kindle. These are the first four books, but I believe the series is up to 18 now.
I am surprised this hasn't been turned into a television series as the Rafferty and Llewellyn characters would be great on screen.
Note: You can upload the first four books free here
From the cover:
Jasper Moon, internationally renowned ‘seer to the stars’, had signally failed to foresee his own future. He is found dead on his consulting-room floor, his skull crushed with a crystal ball and, all, around him, his office in chaos.