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Blood
By: Bridget Stackpole
When most people think of a crime scene they think of dead bodies and blood everywhere; the question is how to do investigators identify who was killed and who is the killer? Well, there are many steps involved and this is not a simple process. When there is blood involved in a crime this evidence can provide information that may solve the case if it is documented, collected and preserved properly. Incorrectly handled blood evidence can destroy facts in a case but if it is properly managed then it can create a strong case.
When forensics investigators first arrive at the scene of the crime they have many tasks to do. First, they must pinpoint the blood. There are different steps that are taken if the blood is wet or dry. If there is dried blood on a piece of clothing or a small object then it is carefully handled and packaged into a bag or envelope, which is then taken to the laboratory where DNA tests are run on the blood spatter. If there is wet blood spotted on a small item or article of clothing it is packaged into a paper or plastic bag and then brought to a secure location where it can fully air dry. After this process is complete, the item is packaged back into the bag and brought to the lab. In some cases, the object of investigation is large and cannot be moved so different methods are used. The first option is to cut out the portion of the object with the dried bloodstain and package the cuttings into envelops, labeled correctly. Another way to go about this it to lift the blood with fingerprint tape by pressing the tape on top of the stain and slowly lift the tape up, placing it on vinyl backing; the stains are labeled and placed in envelopes. One other alternative to collect dried blood on a large object is to scrape the bloodstain into a paper packet by using a sharp instrument to scape the stain. The last scenario that forensic investigators deal with is when there is wet blood on a large item. If the object is large then the bloodstain is absorbed into a cotton square and packaged into a paper or plastic bag, brought to a location to fully dry and then repackaged after it is completely dry and brought to the designated laboratory to finally be tested for DNA to identity the victim.
Blood evidence never should be exposed to heat or humidity. The bloodstained evidence should be refrigerated until it can be brought to the laboratory for testing. When there is blood involved at a crime scene it makes the investigators jobs easier than when there are just fingerprints because blood connects directly to the person of the crime or victim. Blood is the most powerful evidence in a case because it has the power to eliminate or convict a person of a crime.
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