Without giving away procedural tactics on a public site that would "educate" potential criminals, I don't mind mentioning certain guidelines that apply at my agency.
Because of our bailiwick (very large county S.O. with vast desert environment in between Phoenix and Tucson) a large portion of our homicides are "who-done-it-body-drops." (Hey, S.O. ****s, ever try and convince the metro police to take over your investigation after you prove it happened in their jurisidiction? ROFLMAO)
Not putting down the city police (I was one for 20 years) but these are much more difficult to solve. In the city, you can expect scenarios (not all of course) which consist of a 9-1-1 calls about shots fired, or screams heard, etc. This is followed by a rapid response which on occasion results in the arrest of the suspect on or near scene by patrol officers.
If that is not the case, you can expect a more secure and pristine crime scene in that it is a "fresh" and can be sheltered by being inside a structure which "protects" the evidence you are searching for. You can sometimes locate witnesses to the event and it is often easier to establish some type of relationship between the victim and suspect.
On body dumps, the body is usually in an advanced stage of decomposition and has been located by hunters, target shooters, hikers, etc. (We hate dove and quail season out here, lol)
The crime scene environment has been disturbed by weather and animal activity. (Coyotes will drag bones over a large area from the immediate scene.)
You also run across the problem of identifying the victim if there is no I.D. on them, but our success rate is going sky high with new technology and procedures that I will not discuss.
This first step in any homicide investigation is to SECURE the scene.
Some of the detectives on here are going to know what I mean when I say how pissed I get that patrol officers found it necessary to allow their buddies to go see the body, walk through the scene, drive over suspect tire tracks, touch the body, use a friggen phone in the house, pick up a friggen weapon then place it back where they found it, etc, etc, etc…..(dumb, dumb, dumb, dumb)
Good patrol officers and supervisors will stop anyone else from going in, will start tape, will pick a staging area for all vehicles and an entry/exit point for detectives before homicide and crime scene folks even arrive. They will also stop medics from entering the scene and screwing it all up when the victim is obviously DRT (Dead Right There)!
The next step is to wait for the arrival of the crime scene unit, whether it be sworn officers with specialized training, or most likely, highly trained civilian staff.
Crime scene folks do not interview suspects or a witness, which is the job of detectives. (I hate that crap on the show CSI and the main reason I never watched it after seeing it twice.)
Overall photographs are the first thing done. Use the camera to “tell a story”, like a picture board for movies. Because of our environment, we will normally request a helicopter and take photos from the air. This will sometimes help us locate evidence we did not notice at ground level.
After taking scaled pictures of all the shoe soles of all the cops who decided to walk into the scene, we (detectives and crime scene) suit up (protective gear over shoes, torso, gloves, head, known as “bunny suit”) and enter the scene together through a predetermined point which will be used by everyone to enter and exit.
Photographs are taken in stages (picture board) to tell the story later at court, or in a future cold case follow-up. Points of interest are focused on, photographed, then marked for follow-up photographs with markers before measurements and collection.
Crime scene techs are working under the supervision of the homicide case agent. They do what the detective says and the detective is held for final responsibility of how the scene was processed. The working relationship between the two is fluid, however, and the detectives depend on the working experience of the crime scene techs who are encouraged to make suggestions/comments during the scene investigation.
On our agency, especially after the O.J. Simpson fiasco, homicide detectives are to avoid at all costs personally collecting or packaging evidence. This is the responsibility of the crime scene technician. This keeps all the evidence in the control of one person who photographs it, collects it, packages it and puts it into the evidence room. The crime scene tech then writes a detailed supplemental report concerning the photo log, marking and packaging, chain of custody forms and observations/actions on scene.
We want our detectives to be responsible for talking to people, not messing with evidence. I don’t think I will get much argument from fellow investigators when I mention the most important asset of a good homicide detective is the ability to communicate. The second best attribute is the ability to think outside of the box and remain objective. Biggest mistake in the world is to come to a conclusion too early and disregard other leads that come in.
In any event, after the complete scene is photographed and worked for trace evidence, the Medical Examiner’s Office is contacted and they arrange for transportation of the body.
In the best of worlds, although it sometimes does not happen this way, the same detective and crime scene tech will both attend the forensic autopsy. Again, the crime scene tech handles all evidence recovered from the body, and the homicide detective discusses the scene and body evidence with the pathologist.
This policy and procedure is not perfect and there are as many procedures on investigating a scene as there are police and sheriff departments.
Small agencies often do not have the finances to fund a highly trained and equipped crime scene unit, and resort to advanced training to sworn staff or will ask for a mutual aid agency assist from a larger department.
Damn, I tried to keep this short, but as those who have worked these crimes can attest, murder investigations are extremely labor intensive. Patrol sometimes jokes that we are lazy and skate on the job, but they have no idea of the follow-up needed, even with the idiots who shoot their wife, call 9-1-1, wait for patrol to get there, hand them the gun and then fully confess on audio and video.
If someone tells you a case is a “slam-dunk”…….I personally consider them to be a narrow notch above an idiot.
It is my contention there is no such thing as a “slam-dunk” case. Some cases are stronger than others, but there can always be a “surprise” around the corner and a good investigator should expect one.
My two cents worth.
Sorry if I bored and/or offended anyone with my rant.
"No one is compelled to choose the profession of a police officer, but having chosen it, everyone is obligated to perform its duties and live up to the high standards of its requirements." ~ President Calvin Coolidge
“The nobility of policing demands the noblest of character.” ~ Dr. Stephen R. Covey