Grass was Born in the Austrian town of Graz and graduated from the university in his hometown. He spent 3 decades working as a court investigator in Chernivtsi as Bucovina was part of the Austria-Hungary. The huge practical experience he had accumulated led Grass to thinking that crimes could be investigated scientifically. He summarized his experience and developed a system to investigate crimes. His book Criminal Investigation, a Practical Textbook was immediately translated into numerous European languages as it contained a considerable amount of useful knowledge: Gross systematized the police experience of collecting evidence, described criminal lifestyle and slang. He also discussed the ways to apply the latest scientific discoveries in investigation and gave accounts of a number of court cases.
Currently Gross is considered the founder of criminology and criminal psychology. By the way, the very term “criminology” was also coined by Hans Gross: the third edition of his classical book was published under the title A Practical Textbook for Magistrates as a Criminology System. He is also credited with the foundation of the first forensics journal and the Institute of Criminology as a part of the School of Law at the University of Graz.