THE ETERNAL NAZI : FROM MAUTHAUSEN TO CAIRO, THE RELENTLESS PURSUIT OF SS DOCTOR ARIBERT HEIM
by Nicholas Kulish and Souad Mekhennet

He became the world's most wanted Nazi war criminal. Yet, by the end of World War II, he was considered just small fry.
Aribert Heim was a physician, an SS doctor, but he didn't practice healing. Heim euthanized patients with injections of gasoline into their hearts. He would perform surgeries on healthy people at Mauthausen concentration camp. 
In the chaotic arena of the postwar, Heim was able to slip away and actually worked as a reputable doctor in Baden-Baden. He could have just stayed there with his family. But, that was not to be. Heim was alerted that he was going to be arrested and he fled.
A small number of Germans were not willing to ignore the past as the Allies (think Americans) were doing. They wanted to pursue justice and not let Nazi criminals go unpunished. A man by the name of Alfred Aedtner was one of these upstanding citizens. He was a police investigator and it soon became an obsession for him to find Heim. 
The Eternal Nazi is a terrific book. Just when you think there can't be any more sadistic Nazis, out comes another one. It took over five years for the authors to gather all their information from archives, libraries, interviews (Heim's relatives), and a dusty, old briefcase that had correspondence,  medical records, and other interesting ephemera.
It's definitely a suspenseful read and keeps you riveted. Not to be missed.
Very highly recommended.