the travesty of an ending: the movie version of a mind to murder

i was appalled at the end of the movie version of this great mystery novel. i have the sense that someone got bored and/or lazy and did not finish the end of the book. the movie version is a travesty. p.d. james is great for her last minute unexpected plot twists and unconventional endings: recall the private patient or a certain justice (perhaps the best). if she personally approved this script, i'm stunned. the great pleasure of the original conclusion is that you (the reader) along with adam dagliesh think you have everything figured out--and then WHAM! not quite (at least in my initial reading). this book was one of the earliest hints of great things to come. read the book and then watch the movie if you want a hoot as to what screenwriters can do ruin great literary material.