How this novel has been overlooked by so many sci-fi fans, not to mention the Hugo and Nebula awards committees, is beyond me. This is one of the greatest novels of the 20th century in any genre. Read it more than once, and discuss it with your friends (a fair amount of technical knowledge can help you understand some of the more arcane parts, but is not strictly necessary).
"Queen of Angels" is a vivid and deeply philosophical novel about how a future society deals with the crime of murder, as seen through the eyes of a policewoman, a psychiatrist, and a poet. Bear is without living equal in his ability to create convincing future worlds and extrapolate the effects of technology on the human spirit. Along the way, he challenges the reader's fundamental perceptions of self, humanity, mental illness, and justice.
This book is a good introduction to Greg Bear. It has a more-or-less-sequel, "Slant", which is also very good, although I thought the ending of that book was a little too pat. Fans of end-of-the-world fiction will love his "Forge of God" and "Anvil of Stars", which are better than anything Niven and Pournelle have done. Anything by Bear is guaranteed to be an enjoyable read at minimum, and several of his novels are complex and moving enough to stand with the best fiction of any age. I promise, if you are a thinking person, you will not regret reading this book.