The investigation of gunshot traces focuses on the question of whether a suspect has operated a firearm - so-called gunshot hand determination - as well as the question of the distance from which a firearm was fired - so-called gunshot distance determination. This involves analyzing the smoke that leaves the weapon when the shot is fired. As this involves the smallest microparticles in the order of 1 micrometer (1/1000 mm), complex measuring methods such as automatic particle search and X-ray microanalysis in the scanning electron microscope (SEM) as well as the determination of quantitative gunshot residues using X-ray fluorescence analysis (XRF) or mass spectrometry (MS) are used. Smoke distribution images can also be displayed using chemographic color reactions.
In the field of explosives, substances or preparations suspected of containing explosives are analyzed analytically and chemically. The initial aim is to determine whether they are substances within the meaning of the Explosives Act. Furthermore, the substances are chemically identified using various analytical methods. If explosives have been converted, tests are carried out with the aim of sensitively detecting traces of the unreacted explosives or drawing conclusions about the original explosive by detecting the conversion products.
As part of physical investigations, vehicle bulbs are examined with regard to their operating condition at the time of the accident. For this purpose, the filaments are examined at high magnifications in the SEM for characteristic features that can provide information as to whether, for example, the indicators or headlights were switched on at the time of the accident.
Potential narcotic preparations are analysed qualitatively, i.e. characterized as narcotics () within the meaning of the German Narcotics Act. The focus is on herbal products (hashish, marijuana), heroin, cocaine and amphetamine preparations, including other amphetamine derivatives such as ecstasy.
If a positive result for BtM is found, the active substance content of the preparations is determined quantitatively. By determining the active ingredient content and net weights, the judiciary is able to determine whether the so-called "non-minor quantity" of a BtM preparation has been reached, which is relevant under criminal law.
In addition, comparative examinations of BtM preparations are carried out with the aim of identifying or ruling out possible similarities between different BtM preparations, which are important for further investigations with regard to "dealer structures" etc.
In the context of BtM trace examinations, evidence objects that may have come into contact with BtM are analyzed with high sensitivity for relevant BtM traces.
In addition to the types of drugs mentioned, investigations are also carried out into "rare" drugs (including "biogenic drugs", LSD, "liquid ecstasy") and medicinal substances. If illegal laboratories are found, preliminary, intermediate and end products of illegal BtM syntheses are analyzed and, if necessary, the synthesis route is determined on the basis of available documents. In addition, powders, tablets, items of clothing and any poisoned food etc. are analyzed and corresponding toxicological reports are prepared.
In order to determine the cause after fire incidents or room explosions, the fire experts in the fields of chemistry and electrical engineering carry out investigations at the scene of the fire.
Samples taken in connection with fire incidents are analyzed in the laboratory. The aim is to detect any traces of fire-accelerating or fire-promoting substances with a high degree of sensitivity. Seized liquids from possible incendiary devices, e.g. from Molotov cocktails, are analyzed and evaluated with regard to their properties as incendiary agents.
In order to investigate accidents or homicides in connection with electrical energy or following manipulation of electrical equipment suspected of being a criminal offense, electrotechnical investigations are carried out by experts at the scene of the incident.
Electrical devices and components involved in such incidents, as well as those suspected of having caused the fire, are examined for traces of possible defects or tampering as part of laboratory tests.