Forensics Lab Reflection #2

What Scientific ideas or theories would help you explain why you are able to use the procedures to analyze the evidence?

For the Killer Cup of Coffee Lab, and the Ink is Still Wet Lab, The colorimeter helped us infer who the suspect was by using light to determine what the amount of absorbency was at 635 nm, 565 nm, 470 nm, and 430 nm. We were able to use the procedures because we, as humans can’t find the absorbency by just looking at it, we need the accuracy of technology to precisely find the absorbency. For the First Impressions Lab we needed to make the impressions for the teeth, because we wouldn’t be able to make an accurate guess by just looking at the bitten cheese, and the different sets of teeth. Therefore we needed the plates to make the impressions so we could compare and contrast the different teeth impressions, and infer which pair was the suspect’s set of teeth.

How has your approach to lab procedures changed from the first round of labs? Are you more or less confident in you results? Why?

Since the first round of labs I think that I have learned a lot of really good tips from doing various experiments. One that applied to all of the labs was reading instructions. I learned that it is always very important to read instructions so that when doing procedures during the lab, you don’t get confused or have a lot of questions. For example, during the Killer Cup of Coffee Lab, when you had to use the colorimeter and record data it was really important to read all of the directions first. My group didn’t read all of the directions at first, and later we found out doing the rest of the lab to be very difficult, because we didn’t know how to use the equipment properly and we had to ask for a lot of help! Later on when my partner and I had to do, The Ink is Still Wet Lab, it also involved a colorimeter. We knew we had to read the directions because otherwise we would be totally lost. Reading the directions ahead of time resulted in our Lab going fast and very smooth, with little questions asked along the way. Another tip I learned along the way was to work efficiently. For this set of labs I knew we had to work efficiently because some of the labs took longer than others. For instance when working on the First Impressions Lab it didn’t take as long because all we had to do was wait for the plaster to harden, (which took an hour) and all that was left was the teeth imprints. Since that lab didn’t take as long, we used that leftover time to make up for the longer labs. The Killer Cup of Coffee was a longer lab so we decided to finish up the questions after finishing the First Impressions Lab. I think I was more confident in my results because since we have been practicing being accurate, using different tools, using different techniques, and knowing what to look for, it was reassuring to know waht we were doing, and what to expect.

Forensic Lab Reflection

What role do multiple observations/experiments play in making god inferences and conclusions in each case?

Making multiple observations/experiences in each lab helped us infer who was the suspect of the case. If we had only had one or two cases we could not have correctly identified who the suspect was because we would not have enough data or the data we had could have been incomplete. For example when doing the soil case, my partner, Kyra and I had to compare and contrast different dirt. We looked all 5 samples (including the actual crime scene sample) when it was dry and wet, we checked the PH and Conductivity of each sample dirt, and we checked the water absorbency. All of these samples helped us better infer where the dirt was from because we had multiple samples to compare to the actual crime scene dirt. What also helped us in the lab was when we tested the samples in many different ways because for example if we had only recorded the water absorbency for the samples it wouldn't give us enough information to correctly infer which one was from the crime scene.

When is it hard to be precise and how does this affect the confidence in your results? What did you do about this?

I think it was very hard to be precise in all of the labs that we did. Anything could have gone wrong and even the smallest things like misreading the information and not correctly recording it, or misunderstanding how to do a procedure. For example, when doing the bullets lab my partner Star and I had some difficulties when doing the lab, we didn't measure the lands and grooves correctly so we had to re-measure every bullet. After that when we had to try and identify the type of gun it could have possibly come from, the measurements wouldn't match up for the types of guns! Luckily that didn't stop us and we kept working hard at the lab. Sometimes when we knew we weren't going to have very accurate measurements, (like when measuring the lands/grooves on the bullets, or the weighing the dirt in the soil lab), we worked to move around the imperfections and used what information we had to better confirm the data we collected. Once we moved around the imperfections, we had more confidence in our results!

When can you rely on "known" data to match up with and when do you need to generate your own? What's the difference?

The only lab that had "known" data was the bullets lab. We used the known data to compare to our own measurements/observations, and from that, we could infer which gun it was from. The other two labs didn't have any known data to compare to, so we had to generate our own data from the crime scene to compare to the test samples. The difference between the two is that "known" data can be more reliable and sometimes more accurate. When you have "known" data it is already certain that it is correct, but when you have to generate your own data there can be varied answers, and you are never completely certain it is correct.

Blood Splatter

How did multiple drops at each height affect your results? What is the purpose of multiple trials in an experiment?

I think that when we did multiple drops at the same height it would ensure the accuracy of the blood drop/splatter. This would help us because one drop doesn’t really give us much data to be sure we had gotten the right diameter. While 3 drops gives us a good idea of how big the diameter was and what the average is of all three, which gives us much more accurate data. For example, every once and a while during the experiment air bubbles would come and there would be more air than blood. Which resulted in the blood splatter being very small for the height we dropped it at. If we had only done one drop we would have never known the drop should have been bigger. That would give us the incorrect data and it wouldn’t help us later on.

What did you discover about the influence of height on blood diameter in a blood spatter? Could you now accurately infer the height at which a blood drop originated based on the diameter of a blood spatter? Why or why not?

My partner Kyla and I discovered that the higher we would drop the blood from, the bigger the blood splatter’s diameter would be. We also discovered that when we got higher the blood splatter’s diameter got bigger. Also in class when we saw the blood splatter A,B, &C we could infer that A was the most like what we had done because it looked the most similar. And although it was a little bit bigger we could also infer that it was from higher up or from a different angle, because of what we had tested that day. We could do that by comparing the blood splatter’s diameter with the information that we collected.

sound of science

In a tiny town of Paris a woman named Marie opened a restaurant called Mon Amour & Passion. It was in a part of town that wasn’t very often visited and no one knew about her restaurant. Marie took her time making delicious recipes for dinner lunch and breakfast, and yet no one came! Every so often a few people came but that was only one or twice a week. The rent was high and she didn’t know how she was going to be able to keep her store alive. All Marie wanted was to be able to share her food creations with the city of Paris.

As a tribute to her few costumers she decided to invite them to her restaurant for the last few days that Mon Amour & Passion remained. Her costumers came everyday of the week and even some of them brought family and friends. Marie was very pleased and she had no regrets to what she had done with her career. After all she had pursued her lifetime goal to continue on with her zeal of cooking, and also to open a restaurant.

As Marie was packing up her restaurant one of her dearest friends calls her asks her if she has looked at the paper yet today. Marie replies no, and as soon as she ended the call with her friend she dashes to the paper. Marie is absolutely speechless, and not to mention as white as a ghost about what is written in the food section. Front page of the restaurant reviews was her restaurant name, Mon Amour & Passion, and the review below it. As much as she wanted to, Marie couldn’t make herself look at the review. She had thoughts in her mind like was it really bad? Was it really good? Did he/she like what he/she was served? All of these questions racing through her mind Marie was so nervous to even look at the very first word! Finally the she came up with the confidence, and read the review.

“Mon Amour & Passion is not a place you pass by everyday, it is something you might not even know exists. A woman owns this restaurant by the name of Marie Dumont, who by the look of her menu, seems to work very hard on her exquisite dishes. Tasting her food, which was cooked to perfection, brought me to utter astonishment that a restaurant this unknown had such wonderful food. Her warm welcome when I walked in made me feel like a family member and the atmosphere of this cozy restaurant made everything feel like home. Lets just say my visit to Mon Amour & Passion was a delightful evening and I would definitely revisit.”

That one review changed everything in Marie’s life. Marie opened a new restaurant in a more busy part of town, and people came more and more often with big smiles and empty stomachs to try her new creations every week. Marie got everything she had ever wanted and not only did she keep her restaurant running she got to make her own cookbook which she sold to everyone is Paris to share her wonderful creations.