A guilty person will be tortured and possibly killed until they would confess. If lucky then the power of god will guard the innocent.
Swedish chemist Carl. W Scheele discovered a test for detecting arsenic in corpes.
Valentin Ross discovered a better way to detect small amounts of arsenic
Mathieu Orilla published a book about detection of poisons and effects
First Polarized microscope invented.
sperm detection and there was a use of toxicological evidence in criminal trial.
Photographs made recordings much easier
Firs Speculation test on blood
Alphonse Bertillon introduced the Bertillon's system. It identified ones physical appearance. People trusted it for 2 decades. it was sadly later replaced fingerprinting
"Jack the ripper", a serial killer, was never caught for killing prostitutes in the city of london.
Hans Gross published the first book of "Criminal Investigation using forensic science.
Karl Landsteiner discovered ABO Blood Typing
"Questioned Documents" published by Albert Osborn
Edmond Locard stated that , When 2 objects come into contact with each other, a cross‑transfer of materials occurs that can connect a criminal
suspect to the victim or the crime scene.
Los Angeles PD Crime Lab was the first crime lab
University of California at Berkeley Criminalistics
Department led by Dr. Paul Kirk
J. Edgar Hoover opened the FBI National Laboratory.