. . . The Forensic Crime Scene Technician or the Investigating Detective.
The 'lead' investigating officer/detective is in charge regardless of who is "working" the scene.
A crime scene investigator is responsible for collecting and analyzing physical evidence at a crime scene, while a detective is responsible for investigating crimes, gathering information, interviewing witnesses and suspects, and solving cases. Essentially, a crime scene investigator focuses on the physical evidence aspect, while a detective handles the overall investigation.
Act fairly and follow established rules.
The verb that describes detective is "investigating."
analysis
an investigator is a person so you would yous it as a noun ex: The investigator walked quietly into the church. an investigator can be seen as ether a detective, (because they are investigating the crime) or as someone hoping to broaden their religious beliefs (so they are investigating a church)
I met an officer one time. He did not really go to a crime investigating school or education at all, yet he was a former detective and a SWAT member. Working at a local police station can help. After a few years you will get into the detective position if you do well in patrol.
case
Happens all the time. A detective might consult with a computer specialist, a firearms expert, a locksmith, a physician, etc. The are all specialists in their field.
"Homicide" refers to a crime involving murder. Example : "The man committed homicide and was arrested and jailed."
The witnesses and the victims.