2. Includes detailed photography and fingerprinting.
Step-by-step explanation:
The first walk through involves the designing of a a plan to carry out the process of crime scene.
The second walk through is done for the purpose of documentation. This process includes taking pictures and drawing sketches of the scene. It might also involve taking videos of the scene to assure that every detail of the crime scene is documented.
After this step, evidence are collected from the scene.