This is a reply from the last thread, but I still felt it was important to address. Sorry if I'm beating a dead horse.
From MyBelle
"I've repeatedly asked for a link to those "basic investigatory rules" that the LE in this case have breached.
Until such a link is posted, we'll agree to disagree."
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I feel so silly.
I just assumed that in this day and age, with all the crime shows on TV like Law & Order, CSI, NCIS, etc., that everyone was just AWARE of basic crime scene procedure, chain of command with evidence, and that initial processing of the crime scene was absolutely CRUCIAL in getting it properly investigated and it leading to finding the perpetrator/s of that crime and seeing that they are held accountable for it through the justice system. Leaving a crime scene unattended, unsecured and IN THE DARK, and traipsing the evidence all through the town unattended, ruins the integrity of the evidence and in return, the case. You may have the evidence, and know exactly who committed the crime, but if things were screwed up in the beginning through the actions of LE, someone truly could "getaway with murder" and the victim and their loved ones will never see the justice they deserve.
THAT is why Basic Investigatory Procedures are so important to adhere to.
Here is a link that I thought would be a "good start" for you. It has great info in it and was written with the help of several agencies and then distributed throughout many more local, state and federal LE agencies.
http://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/april2000/twgcsi.pdf
CRIME SCENE INVESTIGATION: A Guide for Law Enforcement
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Actions taken at the outset of an investigation at a crime scene can play a pivotal role in the resolution of a case. Careful, thorough investigation is key to ensure that potential physical evidence is not tainted or destroyed or potential witnesses overlooked."
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Procedure:
Prioritization provides for the timely and methodical preservation and collection of evidence.
Collect, Preserve, Inventory, Package, Transport, and Submit Evidence
The handling of physical evidence is one of the most important factors of the investigation.
The team member(s) shall ensure the effective collection, preservation, packaging, and transport of evidence.
The team member(s) should:
a. Maintain scene security throughout processing and until the scene is released.
b. Document the collection of evidence by recording its location at the scene, date of collection, and who collected it.
c. Collect each item identified as evidence.
d. Establish chain of custody.
e. Obtain standard/reference samples  from the scene.
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