Evidence Collection 03/26/15

In this post, I hope to extend my knowledge on the whole process of evidence collecting and the protocol for different types of evidence. Depending on what type of evidence is being collected, there are different guidelines to follow.

"Free Newsletter." Evidence Collection Guidelines. N.p., n.d. Web. 27 Mar. 2015.                         

This site is a crime scene investigator page that provides details on how to collect and preserve evidence for different types of evidence. It lists the types of evidence that could be collected at a crime scene followed by a description of how to collect the evidence without contaminating it.

Blood Stains
 Blood that is in liquid pools should be picked up on a gauze pad or other clean sterile cotton cloth and air dried thoroughly at room temperature. It should then be refrigerated or frozen as soon as possible and brought to the lab as quickly as possible for processing. Delays beyond 48 hours may decrease the value of the sample or even make the samples useless to the investigation.

Dried blood stains:

On clothing - if possible, wrap the item in clean paper, place it in a brown paper bag or box and seal and label container. Don't attempt to remove the stains from the cloth.

On small solid objects - send the whole stained object to the lab for processing, after labeling and packaging.

On large solid objects - cover the stained area with clean paper and seal the edges down with tape to prevent loss or contamination. If it is impractical to deliver the whole object to the lab, scrape the stain onto a clean piece of paper, which can be folded and placed in an envelope. Do not scrape directly into evidence envelope. Scrape blood from objects using a freshly washed and dried knife or similar tool. Wash and dry the tool before each stain is scraped off. Seal and mark the envelope.

Do not mix dried stains. Place each stain in a separate envelope.

Never attempt to wipe dried stains from an object using a moistened cloth or paper

Blood Samples
Autopsy blood samples:
The pathologist obtains the sample directly from the heart into a yellow or purple stoppered vacutainer. In rare cases when there is no liquid blood is available, the pathologist will collect a section of liver, bone, and/or deep muscle tissue and freeze for typing.

Live individual's blood samples:
For typing purposes, have sample drawn into yellow and purple stoppered vacutainers and have a secondary standard just in case.

Seminal Stains

• Seminal stains are often, but not always, found on clothing, blankets, sheets. Allow any stains to air dry, wrap in paper, and package evidence in paper bags. Do not use plastic bags.
• For sex offense cases, the victim should always be examined by a physician. A Sexual Assault Evidence Collection Kit is used to collect evidence from the victim. It is very important that the instructions on the kit be followed with care in order to gain the greatest benefit from the collected evidence.
• Label all garments such as undershorts, panties, or other exhibits and package each garment separately.
• If damp, allow fabric to dry completely before packaging.
• Handle fabrics as little as possible.

Hair

• An examination of human hair can occasionally reveal the possible race of the individual from whom it came and the part of the body from which it originated.
• Human hair can be compared to determine whether or not two samples could have had a common origin. The value of the Lab examinations of such specimens will depend upon the amount of hair recovered and the characteristics found in the examinations.
• Recover all hair present. If possible, use the fingers or tweezers to pick up hair, place it in paper bindles or coin envelopes which should then be folded and sealed in larger envelopes. Label the outer sealed envelope.
• If hair is attached, such as in dry blood, or caught in metal or a crack of glass, do not attempt to remove it but rather leave hair intact on the object. If the object is small, mark it, wrap it, and seal it in an envelope. If the object is large, wrap the area containing the hair in paper to prevent loss of hairs during shipment.
• In rape cases, the victim's pubic region should be combed prior to collecting standard. Get known hair samples from the victim, suspect, or any other possible sources for comparison with unknown specimens. The recommended method for collecting head hairs is to start by having the person from whom they are being collected bend over a large sheet of clean paper, rubbing or massaging their hands through the hair so that loose hair will fall out on the paper. More should then be gathered by plucking them from representative areas all over the head. When the person is a suspect, hair should be gathered from all parts of the body even though there may only be an interest in hair from the head at that particular time.

Firearms Evidence
Firearms:

• Never submit a loaded gun to the Lab, unless it is delivered in person. Unfired cartridges may be left in the mag of a weapon, provided the mag is removed from the gun. A firearm with the cartridge in the chamber should never be shipped by any method, even if the weapon is not cocked or on safety.
• Never clean the bore, chamber, or cylinder before submitting a firearm, and never attempt to fire the gun before it is examined in the Lab.
• Never pick up a weapon by placing a pencil or other object in the end of the barrel.
• Record serial number, make, model, and caliber of the weapon, and mark it in some inconspicuous manner that does not detract from its value before sending it to the Lab. Marking firearms is important since duplicate serial numbers are sometimes found on different guns of the same make and general type. Do not confuse model numbers or patent numbers with serial numbers.
• Place weapons in strong cardboard or wooden boxes, well packed, to prevent shifting of guns in transit.
• Rifles or shotguns should not be taken apart.
• If blood or any other material, which may pertain to an investigation is present on the gun, place a clean paper around the gun and seal it with tape to prevent movement of the gun and loss of the sample during shipment.

Bullets:

• Never mark bullets.
• Wrap recovered bullets in paper and seal in separate labeled pill boxes or envelopes.
• Submit all evidence bullets recovered to the Lab. A conclusive identification may be possible on only one of several bullets recovered even when they all appear to be in good condition.
• Do not attempt to clean recovered bullets before sending them to the Laboratory. Bullets recovered from a body should be air dried and wrapped in paper. Washing may destroy trace evidence.

Cartridge cases:

• Wrap recovered cartridge cases in and seal in separate labeled pill boxes or envelopes.
• Fired shotgun shells may be marked either on the inside or outside of the paper or plastic portion of the shell.
• If an examination is required to determine if a shot shell or cartridge case was fired by a specific weapon, submit the weapon and all recovered unfired ammunition
• Submit all evidence cartridge cases or shotgun shells recovered to the Lab. Some cases contain more identifying detail than others
• Wrap each cartridge in paper to prevent damaging the breech clock, firing pin, or other markings by contact with other cartridge cases. Place wrapped cartridge cases in envelopes or pill boxes. Label and seal container.

These are only a few of the ways evidence should be collected and how they should be packaged and preserved. There are many different types of protocols that are discussed for the different evidence types but there are too many for me to list them all. This page also includes protocols for:

• Fibers and Threads
• Glass
• Paint
• Flammable Liquids
• Tool Marks
• Controlled Substances and Medicinal Preparations
• Questioned Documents
• Latent Fingerprints

At first, I though that the whole evidence collection process would be a lot easier because of how it looks on the television shows, but after reading the contents of this website and actually learning about how evidence is collected and preserved, it is actually a lot harder that I originally expected. It turns out that evidence collectors have to follow a very strict protocol as to not tamper with the evidence. It takes a lot of precision and experience to be an evidence collector. I would feel an immense amount of pressure if I were ever and evidence collector because if I were to mess up, it could skew the results and affect the whole case. Now that I have learned about how to collect evidence properly, I feel like would somewhat know what to do if I were ever put in a situation that required collecting evidence and there was no one there to do it. On the other hand, knowing me, I would probably find a way to mess it up so that might not be the beset idea.