Locard's exchange principle

The Locard'sche rule, also called the Locard'sche principle, is one of the most important principles of modern forensics. It says that there is no contact between two objects can be completed without leaving this reciprocal tracks. It was developed by Edmond Locard, the doctor and lawyer was, but later turned more to criminology.

Justification by Edmond Locard

As early as 1910, formulated by the then director of the French police laboratories in Lyon and co-founder of modern forensics Edmond Locard that no perpetrator to commit an offense or may leave a crime scene without a lot of traces to.

Locard formulated this way:

Importance for the criminalistics

Locards approaches were entirely unusual for that time. For today's law enforcement are essential. Fingerprints, footprints, gunshot residue, fiber traces, blood and semen assignments are often the main load evidence for the elucidation of numerous crimes.

The increasing importance of scientific support for clearing criminal, especially criminal operations, urged the creation of a new, exclusively competent discipline of forensics. Since Locard the importance of the forensic investigation of a crime scene was aware of and has driven, he can be - next to Joseph Bell and Archibald Reiss - described as the founder of forensics.