I have just read a historical mystery by P.F. Chisholm, titled 'The Air of Treason' (published in 2014) in which the author makes use of the detailed findings in the newly-discovered coroner's enquiry to examine the question of who killed Amy Robsart. The book is fiction, but based on a great deal of historical evidence, and I found it a good read and a plausible theory for the killing. Probably not finding the actual murderer, but explaining how it could have happened.