Throughout his life, Hans Gross made significant contributions to the realm of scientific criminology.

[2] This proved to be a poor system as many of the magistrates relied on their personal knowledge and limited facts or evidence.

[2] However, many people opposed this idea developing into a study, claiming that it did not serve true beneficial value except to those involved in the justice system.

[2] Along with studying a person's behaviors, Gross stressed the use of careful judgement due to often misleading evidence.

[3] Gross fully introduced the concept of criminalistics in 1893, a period in which the notion of criminology expanded.

[3] In 1893, his book Criminal Investigations, a Practical Textbook (Handbuch für Untersuchungsrichter als System der Kriminalistik) was published.

[2] Gross especially expanded on body language and the importance of the judge and the witness involved in a criminal case.

[2] Gross strongly focuses on the failings and inconsistencies of the judges and witnesses, the importance of materialistic evidence, and relating facts with reason.

Also, he relates chemistry, physics, botany, secret codes, and the use of blood to further determine facts and motives.

[2] Introducing new investigation and observation techniques, such as crime scene photography and examining fingerprints, changed how the justice system functioned.

[2] His book, Handbuch für Untersuchungsrichter als System der Kriminalistik, contains revolutionary methods and ideas that greatly broadened criminal science.