Step 1: Primary Survey
The process of collecting evidence may look different for each scene based on the circumstances of the crime. But usually, when forensic scientists first enter the scene of a crime, they conduct a primary survey.
The primary survey involves many steps and guidelines that forensic scientists must follow thoroughly. When forensics scientists first enter a scene, they take detailed notes about everything they are able to see in the scene. The notes may include a description of the scene, rough measurements of the site of the scene, any significant or alarming observations they notice, etc.
Along with their written observations of the scene, they take photographs and sketches of the scene in order to view later. When recording the details of the scene through their notes and pictures during the primary survey, the forensic scientist needs to make sure they do not tamper with, move, remove, or contaminate any of the evidence.
Doing so can cause major problems for the investigation and the forensic scientist can face many issues.
Step 2: Developing a Plan for Investigation
After the initial survey of the scene, forensic scientists must meet with the police and investigators to develop a theory before collecting evidence. The forensic scientists receive and share information with their law enforcement partners to help create a theory to carry out the investigation.
The law enforcement officers, such as the police, can conduct interviews with witnesses, which may be useful information for forensic scientists to reach a theory for their investigation.
After theorizing a possibility for the type of crime, the forensic scientists are allowed to collect any evidence that may be useful to prove their theory and solve the investigation.
Step 3: Collecting Evidence
The forensic scientists tend to identify possible evidence during the first step: the primary survey.
After discussing and developing a theory for the investigation, the forensic scientists can collect the evidence they identified during the primary survey and any other evidence they think may be useful to the investigation.
When they begin collecting and storing evidence to analyze, the forensic scientists must wear gloves and be cautious when walking through the crime scene as they collect and handle the evidence.
Each type of evidence is collected and stored through a different process.
The forensics scientists collect larger pieces of evidence first, such as a gun. Then, they move on to collect smaller pieces of evidence such as trace evidence, which is any material that may be transferred during a crime, such as hair follicles, glass, footprints, blood, etc.
If there are very small pieces of trace evidence, like hair follicles, the forensic scientists may use tweezers or vacuum the evidence and analyze it later in the lab. For any imprints they may want to analyze, they will dust and tape for the imprints.
Collecting trace evidence also involves collecting and analyzing blood samples and much more! While collecting evidence from the scene, the forensic scientists must keep an inventory log of all the evidence they are collecting.
The inventory log must include a description and image of the evidence at the crime scene for every piece of evidence collected by the forensic scientist.
Step 4: Analysis of Evidence
The final step is analyzing the evidence collected at the scene of the crime. Each type of evidence is analyzed differently at the lab.
For any fingerprints collected, the forensic scientist may perform DNA processing. This is when the forensic scientist will be using their scientific knowledge to try to help solve the investigation using the evidence they collected.
As they analyze the evidence using various scientific methods, they are looking for anything that may be significant to solve the investigation.
Based on the results of the analysis of the evidence, the forensic scientists may be able to determine the angle of attack, the cause of the crime, the type of weapon used, and more!