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The Scientific Investigation of the Scenes of Crimes

Over the past few years many law enforcement agencies find themselves in a severe budget crunch. This has led them to enact changes in their daily operations. One such change is to hire and train civilians to serve as crime scene technicians.

This method of filling open crime scene technician (CST) slots produces immediate savings in that those who land these jobs do not have to be “sworn” police officers. The benefits are fewer and of course salaries are lower too. Some agencies, however, consider this as an “entry level” position and may, based upon the effectiveness of the individual, pick up the cost of sending a technician to Basic Law Enforcement Training (BLET) when funds are available.

In many agencies a Tatortreinigung Aachen crime scene technician or a crime scene investigator are virtually the same. In some cases the technician is a pay and training level grade below an investigator, But most agencies merely use either term to describe those individuals tasked with the responsibility of locating, evaluating and collecting physical evidence from crime scenes.

To get an idea as to the salary ranges being offered to crime scene technicians I suggest you perform an Internet search using the keywords “crime scene technician jobs,” or something to that effect..

Educational requirements will vary based on the needs of the local area. Most certainly a high school education is a must, but most agencies are seeking a minimum of an Associate Degree in any of the following disciplines: Forensic Science, Criminalistics, Criminal Justice, Chemistry, Biology, or related field from an accredited community or junior college or technical institute.

Definitions related to the work of the crime scene technician.

These evidence procedures and the order in which they are completed may vary from one agency to another-based upon established protocols. The following procedure is offered as a generalized approach to investigating a crime scene.

Physical Evidence:

Criminal investigation involves people and/or physical objects–things. Crimes are committed by people, but they use certain physical objects to commit these crimes. It is these things used or touched by criminals that constitute what is referred to as physical or forensic evidence.

Scene Security:

The specific duty of the first official to arrive at the scene of a crime is to protect and preserve life and property (offer aid and assistance to those present, apply first aid and summon the necessary medical help); and then ensure the security of the crime scene by erecting barriers (crime scene tape) and posting sentries at all possible entrances and exits.

Conduct a Visual Survey of the Scene:

The initial walk-through will include a visual survey of the scene, making note of any potential physical evidence. Preliminary photographs and/or video are taken at this time.

Conduct a Thorough Scene Search:

Depending upon the complexity of the scene, more than one technician will be required for the search. Potential physical evidence is located and marked with flags, signs or evidence tents for later close up photos and collection.

Maintain a Written Log:

As the search progresses a written log of all findings is kept.

Prepare a Crime Scene Sketch:

A rough sketch is begun for both indoor and outdoor crime scenes. The sketch will mark the locations of visible evidence and accurate measurements are taken to detail the exact location of each “thing” noted.

Process the Scene for Latent Fingerprints:

Using either latent print powders or chemicals, as the type of evidence requires, any physical object that may have been touched by the perpetrator will be processed.

Perform Preliminary, Presumptive Tests for Physiological Fluids, Narcotics and Drugs:

While confirmatory lab testing will also be required, physiological fluids and drugs should be subjected to presumptive, non-destructive field testing methods.

Collect and Package All Physical Evidence.

This is one of the most critical functions of the CST. Court cases do not take place after a week or so following the investigation. It may take years before a criminal trial occurs. Evidence must be collected, marked and preserved with this thought in mind. For example: DNA and physiological evidence may degrade and become useless over time if steps are not taken to preserve it. Blood and semen samples can lose their value if packaged in plastic containers-especially if they are collected while still in a liquid state.

As you may plainly see-crime scene investigation is a complex task that must be completed using scientific principles and guidelines. Many criminal cases have been lost in court because forensic evidence was either mishandled, misinterpreted or was completely absent. The CST is a vital link in the chain-of-evidence, and it is a position that requires sincere devotion to the tasks at hand. The purpose and the integrity of the crime scene technician-as is the evidence he/she collects-are both on trial.