What is the author's style in Death of an Expert Witness by P. D. James?

P.D. James is a highly-respected mystery writer. Part of the reason is because her books tend to be more literary than the pulp fiction kind of mystery novel. Because of this, the vocabulary is very specific and somewhat sophisticated, and many high school students probably need to have a dictionary handy if they want to understand each word. Coupled with the somewhat sophisticated vocabulary is the fact that James is an English author and therefore uses a number of words and spellings that are specific to British English versus American English. Neither the British terminology nor spelling variation should hinder the average reader.