Expirated Spatter: Often caused by internal injuries and seen at crime scenes where victims exhaled after blood mixed with oxygen in the lungs or wind pipe. The blood will either come from the nose or mouth. The stain on the scene could tell the investigator if the spatter came from the nose or mouth depending on the size and density of the stain. For instance, if the size of the stain is rather large and dense it most likely came from the mouth, while if the size of the stain is smaller and dense it most likely came from the nose. If the size of the stain were large and spread out or not dense then the spatter most likely came from the nose but from a greater distance than the victim being directly over the area that the stain is located.

Cast-Off: Generally in a linear or quasi-linear pattern with drops that have tails that point in the direction of the motion. The size of the drop can help an investigator determine the size of the object that caused the pattern. For instance, if a pattern has larger drops than another pattern it can be determined that the larger pattern is from an instrument like a glass bottle vs. the smaller pattern which was most likely caused by a knife being waved around.

Documentation is fairly simple but requires a great number of details. According to the National Forensic Science Technology Center (2013) prior to collected blood stain evidence, the stains must first be photographed and the method that is favorited is high resolution photography (National Forensic Science Technology Center, 2013, p. 10). The photographs will generally contain some form of measurement device to show the size of the stain unless the stain covers an entire wall in which case measurements will only be held in the documentation of the blood stain. The most concise way to photograph and document blood stains is to take an overall picture of the scene and then grid off different areas in a logical fashion followed by documentation of each blood stain depending on the grid location of the stain in order to maintain an organized note and scene. This allows for corresponding labels of the stain samples along side the grid labels following documentation.

2. Skeletal remains

Some of the information on the excavated remains seems a bit misleading. Matching information from our reading however includes information about the skull including the brow ridge and the mastoid process as well as information about the clavicle and the epiphyseal union. According to Forensicmd (2010) males have the more prominent or pronounced brow ridge which is also called the supraorbital ridges (Forensicmd, 2010, p. 7). Forensicmd (2010) also states that there is not a specified year or age that the epiphyseal union occurs but a range can be determined such as with the medial end of the clavicle and it’s epiphyseal union which takes place between 18 and 30 years of age (Forensicmd, 2010, p. 17). So far we can determine that the remains that were found belong to a male that is between the age of 18-30 but the sex is only an 85% chance of being correct as it was determined with the skull and not with the pelvic bones which would provide a 90% accuracy instead. Race is a bit more tricky to determine considering the fact that we don’t have any long bones with which to determine height and assist in determining the race without a doubt but based on the brow ridge and it’s prominence we can determine that the remains most likely belong to a Caucasoid. The only information not accounted for based on the information provided is the mastoid process. The information provided in the lesson seems inaccurate in determine age, sex or race with the mastoid process. The provided information states that the male mandible has a larger body height than the female and that the male mandible also has a more broad ascending ramus but goes on to show a picture of a male and female mandible with the opposite being true.

– Jessica Ewers


Forensicmd. (2010). Identification of skeletal remains. Retrieved from https://forensicmd.files.wordpress.com/2010/11/identification-of-skeletal-remains.pdf

National Forensic Science Technology Center (2013). A Simplified Guide to Bloodstain Pattern Analysis. Retrieved from http://www.forensicsciencesimplified.org/blood/BloodstainPatterns.pdf

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