Crime and Science, by Jurgen Thorwald
My freshman college roommate gave me a copy of this book for my birthday, and I know it played a huge role in why I pursued a master's degree in forensic science (even if it's one I never used, except as fodder for writing about crimes of all kinds.) Thorwald writes with exceptional clarity about cases obscure and famous solved with forensic techniques like blood typing and elemental analysis of gunshot residue. DNA and CSI-style glamorization makes those older techniques seem quaint, but current criminalists owe a lot to their chemically minded pioneers. It still amazes me that this book and its earlier companion volume, The Century of Detective — which lost the Edgar Award for Best Fact Crime to In Cold Blood — have yet to be rescued from out-of-print oblivion.