Let’s go to the very beginning of an investigation. Nowhere is the adage "first things first" more appropriate than at the scene of the crime. And by the way, the police officer may not be the first person to arrive at the crime scene. He who discovers the body or the lost article should report it to the police immediately because, in the process of rendering first-aid, checking for signs of life, handling objects, he may inadvertently alter and destroy pieces of evidence. But that is simply the unavoidable consequence of a more important duty, and no blame should be attached to the person.
The police officer arrives with a team called Scene of the Crime Operations (SOCO) composed of six members. They are the team leader, photographer and photographic log recorder, sketch preparer, evidence recorder/custodian, evidence recovery personnel, and sometimes a specialist of sorts who has the expertise to solve the crime puzzle. Ideally, all of them should be at the crime scene.
They secure the crime scene and isolate it from people who have no business being there. Unauthorized persons – such as spectators, newspaper reporters, television crews, and people milling about – are kept away from the premises because they may innocently obliterate crucial evidence. It is necessary to cordon off the area with rope and a "Police Line Do Not Cross" tape.
Also, you may have noticed how a photographer takes photos of the crime scene on TV shows like CSI. It’s the same procedure in our country. Each individual item of evidence is not touched or removed from the scene until a photograph is taken.
The investigator recognizes objects of value because it is impossible to restore a piece of evidence to its original position once it has been moved. The crime investigator has to reconstruct the actions of the criminal and test his theory for logic and consistency.
He knows he is a witness to a crime when he affixes his signature to items discovered, with the names of witnesses to the discovery. The signature of the officer-in-charge of the evidence to determine the sequence of events is always recorded.
Physical examination of glass fractures/fragments, paints, firearms, documents, bombs, fingerprints, footprints, tool marks and debris from a fire or an explosion must remain untouched, properly collected, handled, preserved and documented by the crime investigator. They should be left in their raw, purest form until the SOCO team arrives.
The searchers or evidence-recovery personnel, are, of course, looking for anything that might provide a clue. They seek what could shed light on the corpus delicti or facts on the crime scene in question. For example, an empty moneybag at the rear of a store that’s just been burglarized is evidence of the perpetrator’s modus operandi. A glasscutter used to break in is another evidence the same way an ejected shell from a gun sheds light on the perpetrator’s capabilities. The searchers lift fingerprints from windowsills, weapons, tables – any place suspected of having prints.
Trace evidence, such as hair and fibers, dirt, fillings, any particular matter – are picked up with forceps or a spatula. The documents and fingerprints are wrapped in paper and placed without folding in cellophane envelopes for the evidence custodian. All items are tagged and delicately handled.
Bullets and shell casings are wrapped in cotton in separate bottles, and pieces of clothing with stains are collected. In fact, garments should be folded carefully in clean, white paper. White paper is also inserted in between the stains, and placed in a suitable clean box for transportation. Liquid blood is deposited in a test tube using an eyedropper.
The sketcher or the measurer diagrams the immediate area of the scene and its directional references. His work, once completed, signals the removal of the barricades. The premises are returned to the occupants, and he can visit the scene again but not pick any "forgotten" pieces. The crime scene can’t ever be identical to the conditions in which he found it.
At the NFSTI, mysteries are taught to be solved by the police investigator through the examination of blood, semen, hair, fibers, saliva, vomit, perspiration, footprints, shoeprints, fingerprints and what-have-you! These are pieces of evidence unraveled from the crime scene that help solve a crime.
They also teach personnel about instrumentation, which includes the use of polygraph machines, single-reflex camera, ultraviolet, and (here goes!) visible spectrophotometer, fourier transform infra-red spectrometers, mass spectrometers and high-performance liquid and gas chromatograph. All these equipment are used to examine various specimens submitted to a crime laboratory.
What the eyes can’t see, the powerful crime scope police officers carry around with great care discovers latent prints on carpets, blood and seminal stains – any marks! This highly sophisticated instrument can be found in the National Forensic Science Training Institute of the Philippine Public Safety College where I work.
Remember: don’t touch anything at a crime scene. Wait for the men and women in blue.