Trace (criminalistics)
A trace in the criminalistic sense is an object or a reference as material evidence that is used as an indication or evidence for an act , a perpetrator and / or participation in an investigation .
Traces are searched for, secured and evaluated with the help of forensic technology (trace comparisons). The doctrine of traces is called trace research . The traces are secured, analyzed and evaluated by the police ( identification service ) through the forensics department . The overall view of the tracks results in the track image . After completion of the police investigation, they are handed over to the public prosecutor's office as evidence (neuter) and as a report ( forensic evidence report ) . Many traces can be found at the scene of the crime , on the escape routes , on victims and on agents . Basically, a distinction must be made between immaterial and material traces. Immaterial traces are human behavior and personal evidence, such as B. Witnesses.
species
A basic distinction is made between traces of form, traces of material, traces of situations, dactyloscopic traces and traces of objects. Further types of traces are fictitious traces or traces of deception, which, however, are unusable.
Traces of shape
Form traces (more precisely: technical traces of form) are the changes in the shape of an object caused by the action of a tracer. Criminalistic conclusions (as clues or evidence ) can be drawn from the shape of the trace, specifically with regard to the causal subject or object.
- Subjects
- Stab or gunshot wounds
- Scratches, etc.
- Objects
- Tools, especially an individual means of action
- other parts, e.g. B. finger rings, jaws
Traces appear as prints ( print tracks ), impressions (pressure marks), lubricants called (sliding tracks), cuts (cut tracks) and fractures or cracks (breakage or cracking traces).
- See also: Photogrammetry # Close-range photogrammetry , strip projection , three-dimensional laser-based crime scene survey
Traces of material
Material traces are residues of an object (e.g. abrasions, drives, chips). These can be mineralogical , biological or chemical traces. Since ancient times are traces of blood used to infer the sequence of violent crime. Body odor samples are a rarely used form of trace in criminology ( odorology ). The odor test is indirect evidence, so-called circumstantial evidence.
Situation traces
Situation traces describe the arrangement, position and assignment of traces (trace position) or objects to one another and to their surroundings. They are not examined, but only processed for the purpose of reconstructing the course of events (creation of a chain of evidence).
Object tracks
Traces of objects are material traces that are relevant to evidence, for example tools and other (tangible) objects. A classic object track would be e.g. B. an instrument left by the perpetrator, such as a knife.
Dactyloscopic traces
Dactyloscopic traces are prints or impressions of fingers ( fingerprints ), palms and feet in the form of the papillary lines of the skin and are created by them
- the transfer of substances from the skin (sweat and sebum),
- when touching smooth surfaces,
- the transfer of a medium such as paint or blood,
- the impression in deformable mass such as wax or adhesive tape.
Their status is based on the basic assumptions of uniqueness, immutability and classifiability.
The palm and soles prints must always match at least 18 anatomical features when compared. In the case of fingerprints, 12 minutiae are sufficient to clearly identify a person.
Regulations in Germany
Traces that may be used for criminal proceedings or for administrative fines must be secured by the police, d. that is, they should be seized or confiscated . In Germany, entire buildings, grounds and rooms can be secured (by barring, sealing). Non-suspects who destroy or change traces can be prosecuted in Germany for obstruction of punishment .
For the German police, the instructions on crime scene work - traces (formerly the crime scene work guide ) of the Federal Criminal Police Office are binding.
Faked tracks
Faked traces are traces of form, material, situation and / or object that were deliberately laid by the perpetrator in order to consciously distract from the actual (unconscious / latently left) traces.
So they serve to distract the investigators from the real leads and lead them on a "wrong track".
Traces of deception
Traces of deception are traces that are also found at a crime scene, but are not related to the actual crime. There are traces that were previously there or that were added afterwards, which can unintentionally mislead the police, or traces that are dragged from one crime scene to another due to improper work on the part of forensic agents.
Example: At 08:00 pm, a happening burglary in a house. The only trace the perpetrator leaves fingerprints (DNA or forensic trace, in this case a dactyloscopic trace) on the window. At 10:00 a.m. the postman brings the mail and throws his cigarette butt (object trail) into the garden. This is also a trace, but it is not related to the act. The police arriving at 12:00 p.m. found both tracks and did not know which one was from the perpetrator. Hence, it picks up both of them, which can be very confusing. This cigarette butt is consequently a false trace, but this only becomes apparent after the trace has been evaluated.
In the period from 1993 to 2009, based on matching DNA traces at around 40 crime scenes, the so-called " Heilbronn Phantom " was suspected to be the perpetrator . It was not until March 2009 that it was discovered that the cotton swabs used by forensic investigation were contaminated.
In the Peggy Knobloch case , the police found DNA traces of the right-wing terrorist Uwe Böhnhardt at the skeleton site in 2016 . Later it turned out that it was a fallacy, with which it remains unclear how it got to the Peggy's corpse site, and a connection between the two cases can be ruled out with a probability bordering on certainty.
Individual evidence
- ↑ Jana Stegemann, Felix Hütten: Peggy case and NSU series of murders: A dead girl, the DNA of a terrorist - and many questions. In: Süddeutsche Zeitung , October 14, 2016.
- ↑ Olaf Przybilla : Peggy case: Suspicious find was part of Böhnhardt's headphones. In: Süddeutsche Zeitung , March 8, 2017.
