The police investigation is the systematic process that law enforcement officials follow in order to gather and analyze evidence, interview witnesses and solve crimes. It is an essential part of criminal justice and one mistake can destroy a case or even wrongly set a innocent person free.
As soon as a crime is reported, police begin their investigation by securing the scene. Once this is done, they document everything that is there in an orderly manner to provide a clear record of the scene for prosecutors and investigators. They also start a log of everyone who enters the area to ensure that no one accidentally contaminates any trace evidence or inadvertently interferes with the crime scene.
They then interview witnesses, which could include the victim, if they consent to this. Detectives will also speak to anyone else who may have information, such as the suspect’s family, friends and colleagues. They may also request the right to use surveillance to further their investigation, including monitoring a person’s movements or accessing their social media accounts. This is particularly common in drug offenses and other serious felony cases.
Once they have all the facts they can, detectives then send their file to the Public Prosecution Service (PPS). The PPS will decide what charges if any will be brought against the suspected offender. During this stage of an investigation, the police are allowed to seek advice and guidance from their legal department.