Many criminal cases hinge on the information that is collected during the investigative process. Understanding how the investigative process works can often help people who are facing possible criminal charges. The way that this process works can vary from one case to another; however, there are some basic components that remain fairly constant in almost every investigation.
When a crime is still in progress, the investigative process will usually start at that point. The police officers will usually arrest the suspect right then and collect evidence. If the crime was recently committed, the police officers will likely begin to interview witnesses and collect evidence while they process the scene of the crime.
For unsolved crimes, the police officers, often detectives, who work on the case will attempt to gather any evidence they can. This can be through canvasing the area, trying to get fingerprints or gathering items that might have DNA evidence on them.
Throughout the process, whether the arrest occurs immediately or an extended period after the crime is committed, it is crucial that the people handling the investigation respect the rights of the suspect. This includes their Fourth Amendment rights, which protect them against searches and seizures that aren't legal.
If you are the center of an investigation, you should make notes about what is going on. This information might be useful as you begin to build your defense because the method in which the evidence against you is collected might have an impact on your case. It is crucial that every possible option is considered.
Source: FindLaw, "How do the Police Investigate Crimes?," accessed Oct. 20, 2016