Lab Reflection

Paola Ginel
October 3, 2014
Advanced Forensics

Lab Reflection

     On September 8, 2014 at 11:57 am we set up a pork shoulder in a cage outside of Tolman just before the river. The purpose of this experiment was to have a greater understanding of forensic entomology and to witness the development of maggots and decomposition. Over the course of two weeks we let nature take its course and went back to the site for collection and.observation. By the end of this course, we will have had our own mock experience as forensic entomologist.

     From day one the pork shoulder commenced its process of decomposition. As the weather and insects affected the shoulder, it began to change in color and smell. At first, the meat was fresh, odorless (aside fron the typical smell of raw meet) and red in color. The next time we visited the site the shoulder had developed a foul smell, that of spoiled meat, and the texture was more of a leather type. Each day we went the pork seemed to lose more color and get darker. The smell had increased incredibly, and was more than detectable.from.a good distance away. Towards.the last few days the smell was intense and the por shoulder had become in color and was completely decomposed and dry.

     Other changes observed were the insects that colonized on and inside the shoulder. As soon as we set the shoulder down, flies were attracted to it almost instantaneously.  Two days later on the 10th, there were still small flies around but there were also larvae on it. We identified some of the flies as Greenbottle and Sheep flies. There were also other insects further on such as news ans wasps.

     As the days progressed we collected the maggots from their maggot mass. They were slimy from the secretion of enzymes that helped break down the proteins in the meat. Each time we went, the maggots had transitioned from one instar to the other until they had migrated away from the body, into the soil and pupatate. The body was left dry, with some maggots still on board, but not as many as originally noted. This tells us, these maggots were laid at different times.

      After collecting all of our data, we then analyzed it and observed the preserved maggots from those couple of weeks. When looking at out data and comparing it to published data we could see that it was consistent. The maggots developed at an adequate rate in correlation to the temperature. They did grow at different time since they weren't all laid at the same time.

     Lastly, the life cycle of insects are always constant which makes entomology such a great tool for crime.solving. Once you identify a particular species, you can look at their life cycle and trace back to when they were colonized. When this is done, it Gives a time frame from the earliest the latest possible time of the crime. This could be the difference between a faulty alibi and someone walking out free.
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