Microbial forensics

by Joshua Abraham, Garrett Ladignon, Kenneth Ly, and Katarina Jevtic

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DISCLAIMER: the following text is a work of fiction, not an actual forensics report.

Forensics Report

Division of Forensics Science
County Medical Examiner’s Office
Wood, Abrogio: Final Analysis of Bacteria Cloud

1. Background of Crime

At approximately 7:40pm, on Tuesday February 11th, a 911 call was sent to the Police complaining of a loud noise at the neighboring apartment. At 7:50, police officers arrived at the apartment where screaming and loud noise was heard. At the apartment they found Mr. Ambrosio Wood lying dead on the floor. The Medical Examiner’s team was called to the scene. Based on their autopsy it became evident that Mr. Wood was strangled to death at the neck, and died at 7:45pm on the 11th.

Detectives went through Mr. Wood’s phone, email and computer records and also talked to his neighbors, friends and colleagues. None of the interviewed reported anything remarkable. While his email and computer records were unremarkable, it was evident from text messages that Mr. Wood had a verbal argument the previous evening with his girlfriend Ms. Arabella Pearson. The CSI technicians that secured and recorded the crime scene found hair on the body and at the location in the neck where Mr. Wood was strangled. Ms. Arabella Pearson was considered a person of suspect and her DNA was collected. The DNA from the hair matched that of the DNA collected from Ms. Arabella Pearson. The CSI technicians were unable to find any fingerprints at the scene except for the deceased’s own, and the only other hair and blood on the scene was that of the deceased’s. The prosecutor believed that the verbal argument and the hair at the scene where enough to get an arrest warrant for Ms. Arabella Pearson.

Upon interviewing Ms. Arabella Pearson, she claimed her phone was missing and therefore she had no idea that Mr. Wood had died. Upon telling her that her hair was found at the scene, she explained at the she had an identical twin with the same DNA and hair color.

2. Microbial Analysis

Detective Johnson was able to confirm that there was an identical twin, named Desdemona Pearson. Mr. Johnson also ordered our Office to perform a bacterial analysis.

Every human being has a unique number and types of bacteria living within their body. The collective groupings of all these bacteria are called bacterial or microbial clouds. Each human being’s cloud is unique and is a product of their environment, their hygiene, their profession, their living conditions, their friends etc. Microbial clouds start forming during birth and are not based on a person’s genes, and therefore even identical twins will have different microbial clouds.

The medical examiner gave us Mr. Wood’s bacterial cloud and we were able to confirm that this was Mr. Wood’s bacterial cloud as our technicians went back to the crime scene and found the same cloud in Mr. Wood’s clothing and utensils in his apartment. A second sample was taken from the site of the body where strangulation occurred, this cloud was compared with the cloud found on Mr. Wood’s clothing and utensils to make sure we had not taken Mr. Wood’s cloud again but rather the cloud of the person who strangled Mr. Wood. We also isolated the bacterial clouds of both Ms. Arabella and Desdemona Pearson. Our technicians also went to both persons’ apartment to confirm the cloud using their own clothing.

All four clouds were run under a Nicolet™ iS™50 FT-IR Spectrometer from Thermo Scientific. The IR spectrometer analyzed the bacteria and produced a unique signature based on the unique type and number of bacteria in each person’s cloud. An IR spectrometer is able to detect unique molecular structures based on the fact that each molecule absorbs different wavelengths of light.

3. Samples
  1. Mr. Wood’s cloud (obtained from clothing and utensils)
  2. Bacterial cloud found on neck at point of strangulation (compared with Mr. Wood’s sample to ensure difference)
  3. Ms. Arabella Pearson’s cloud
  4. Ms. Desdemona Pearson’s cloud

4. Matches

Sample 2 and Sample 4.

5. Final Findings and Conclusion

The signatures found on sample 4 were virtually the same as the signatures found from Sample 2. Therefore we can conclude that that the person who strangled Mr. Wood is the same person whose cloud is represented in sample 4. There is no evidence that the person whose cloud is represented in Sample 3, was present or touched Mr. Wood while the crime was committed.

Dr. Mittal
Chief Forensics Scientist
County Medical Examiner’s Office

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