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Updated: Oct 11, 2022

Criminal investigation is a multi-faceted, problem-solving challenge. Arriving at the scene of a crime, an officer is often required to rapidly make critical decisions, sometimes involving life and death, based on limited information in a dynamic environment of active and still evolving events. After a criminal event is over, the investigator is expected to preserve the crime scene, collect the evidence, and devise an investigative plan that will lead to the forming of reasonable grounds to identify and arrest the person or persons responsible for the crime.

Criminal investigation is not just a set of task skills, it is equally a set of thinking skills.

Investigative tasks relate to the information gathering processes that feed into investigative thinking and the results. Investigative thinking, on the other hand, is the process of analyzing information and theorizing to develop investigative plans. Investigative tasks relate to identifying physical evidence, gathering information, evidence collection, evidence protection, witness interviewing, and suspect interviewing and interrogation. Criminal investigation is aimed at collecting, validating, and preserving information in support of the investigative thinking process.

For an investigator speaking to the court, this process needs to be clear and validated through the articulation of evidence-based thinking and legally justifiable action.

To be acceptable to the court, it must be done in a structured way that abides by the legal rules and the appropriate processes of evidence collection. Additionally, it must be a process the investigator has documented and can recall and articulate in detail to demonstrate the validity of the investigation.

Each piece of relevant evidence will be considered based on its “probative value”, which is the weight or persuasive value that the court assigns to that particular piece of evidence when considering its value towards proving a point of fact in question for the case being heard. This probative value of evidence goes towards the judge, or the judge and jury, reaching their decision of proof beyond a reasonable doubt in criminal court, or proof within a balance of probabilities in civil court.

A witness is a person who has seen an event or who testifies about what he has seen.

Ideally, every witness would be an upstanding member of the community with a high level of integrity and an outstanding reputation. This is rarely the case. The nature of criminal activity and the natural proximity and association of criminals within a criminal community, often skew the witness list more towards those with more colorful and less upstanding personal profiles. Being part of the criminal community, or having a criminal record, does not necessarily mean that a witness will not be truthful. However, these are factors that an investigator must consider when assessing the value of the evidence being reported.

The use of physical evidence at the scene of the crime and the use of deductive and inductive reasoning to gain knowledge of the events surrounding the crime. Crime scene investigation is multidisciplinary and involves a systematic search of the crime scene, meticulous observation and documentation of the scene, photography and sketching of the scene, the identification, processing and collection of physical evidence such as fingerprints, footwear impressions, hair, fibers, biological fluids, and materials for DNA analysis, and perhaps most important, the application of careful reasoning to the facts.

Although other documents will be created by the investigator to manage the crime scene, no other document will be as important to the investigator as the notebook. The notebook is the investigator’s personal reference for recording the investigation.

At the end everything starts from the crime scene. The crime scene is any location where the crime happened or any area that contains evidence of that crime. The first and most important step is to secure the scene by the police officers who first arrive at the crime scene where the crime took a place.

The purpose of crime scene investigation is to help establish what happened and to identify the responsible person. This is done by carefully documenting the conditions at a crime scene and recognizing all relevant physical evidence. The ability to recognize and properly collect physical evidence is oftentimes critical to both solving and prosecuting violent crimes. It is no exaggeration to say that in the majority of cases, the law enforcement officer who protects and searches a crime scene plays a critical role in determining whether physical evidence will be used in solving or prosecuting violent crimes.

About this and much more, we will talk in our next webinar “ Introduction to criminal investigation”, which is available only for IPO members on August 14. at 12 PM Rome time.

To apply, send your full name, IPO ID Card number, or IPO Membership Certificate to:

We also remind you all that in order to join the IPO, it is not necessary to send an email for membership request, as well as to send documents that are not required by us, you can apply directly in the link below to one of the relevant categories in which you meet the criteria to join the IPO >>>>

Police Officer, Crime Analyst

General Director of IPO Headquarters &

IPO LED - Law Enforcement Department

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