Projects:2016s1-142 Code Cracking: Who Murdered The Somerton Man?

File:Test.jpg== Topic ==

Code cracking and data analyzing.

Supervisors

Prof. Derek Abbott

Dr. Matthew Berryman

Team members

Yifan Ma

Yami Li

Executive Summary

The Somerton man case is a very famous unsolved case which related to an unidentified dead man on Somerton beach in Australia. The aim of this project is to find out the new clues about the Somerton man case by comparing the content of various elements in the dead man’s hair with the hair of the normal man. In this project, the main research method consists two part, one part is the spectral analysis and the other part is the comparative analysis. For spectral analysis, through burning and scanning hairs extracted from Somerton man and control samples, the hair data with respect to elements content can be recorded. In this experiment, two set of data which are glass and quartz plate test are obtained. In theory, the purity of the quartz plate is higher, so the results of spectral analysis should be more accurate. However, in view of the fact that the hair sample during the quart plate test was not complete compared with glass plate test. Thus, the test data from both experiments are utilized for comparative analysis. The hair data comparison between Somerton man and control samples are processed by Matlab programming. The reason for choosing Matlab is that it can express the distribution of each element in the hair of Somerton man and control samples clearly. These significant and small differences in content are the focus of this project.

Acknowledgements

Thank Prof. Derek Abbott for his guidance, advises and explanations. He teaches me to understand the documents referred to this project and gives me useful feedback which improves my work quality. To James Chapel for his assistance on data analysis and plotting figures. To Dr Hong Gunn Chew for his guidance on the project schedule.

Task 2

Introduction

This project is to study on an unsolved murder case that happened on the 1st of December 1948. At 6:30 am of that day, a man was found dead on Somerton beach. This dead man carried with no identifications and his teeth were not matched with any known person, so he is called Somerton man. After postmortem, the coroner picked some information from this dead man, such as the heart was of normal size and the death time was around 2 am of the found day. Besides, the coroner figured out that approximate three to four hours before death the man ate a pasty as meal which pathologist Dr. Dwyer suggested some poisons causing the man’s death. But the pasty should not be the source of poison through further research. Finally, after a series of investigations, the coroner still could not tell any conclusion about this man’s identity or cause of death and the dead man’s body was buried in Adelaide's West Terrace Cemetery in 1949. It became one of the Australia's most fascinating cold cases. [2][4][10] In order to continue the study of this case, a plaster cast of Somerton man was made in 1949. The hairs which were extracted from Somerton man plaster cast and other six different students are used for spectral analysis. [9] Hair data is recorded by Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and this instrument is effective for micro-sampling of solid material for trace elements and the analysis of predominantly cation. [1] For collecting data, the hairs were burned by laser. Then, the instrument measured the levels of different isotopes and the relatively values of elements. After testing, the comparison for experimental results between Somerton man and six other different students can be processed.

Motivation

The aim of this project is to find out the new clues about the Somerton man case by comparing the content of various elements in the dead man’s hair with the hair of the normal man. Even if the case has happened for decades, it is not been forgotten. The residents still would like to see the case solved. In addition, this project can expand the knowledge for data analysis, code cracking, engineering statistics and digital forensics. In fact, this dead man was suspected to be a foreign spy due to his unknown identity. So, it is meaningful for country security as well.

Objectives and Methods

1.Understanding the hair biology knowledge and some related chemical knowledge. 2.Hair mass spectral experiment: hairs were burned by laser. Then, the instrument measured the levels of different isotopes and the relatively values of elements. The scan speed of mass spectrometer was 5 micrometers per second. 3.Two tests: For glass test, the scan length of each control sample was 1000 micrometers. The method length was 230 seconds including 30 seconds background. The scan length of Somerton man’s hair was 6054.6 micrometers and the method length was 1240.9 seconds including 30 seconds background as well. For quartz test, two sections of seven control hairs have been tested and each hair is 500 micrometers, so there are fourteen control hair data and the total length is 0.7 centimeters. Somerthon man hair scanned 500 micrometers, each subsequent transect beginning where the previous finished for a total 96 sections (4.8 centimeter total) due to the limitations of the sample stage.

4.Experiment results analysis: For a healthy person, the hair growth rate is approximate 0.4 millimeters per day [7]. So based on glass test data we can get about 2.5 days information of control and 2 weeks information of Somerton man before his death. From the quartzes test data we can also know the element content differences between Somerthon man and control samples hair. All the experiment data is plotted by Matlab and the plotting figures are listed in Appendix A. Then, the comparison between Somerton man and control samples is processed. The comparisons are focus on the different elements content in hair which can provide some useful information related to Somerton man. 5.Put forward some reasonable assumptions and new clues: Based on experiment data analysis, some reasonable assumptions needs to be presented. These assumptions can be related to some activities and the living environment before his death. 6.Validation of assumptions and clues: Once these assumptions are confirmed, they can be served as new clues for the case to provide more direction.

Literature Review

1.Previous Studies In addition to police men’s investigation, there already have several academic studies. Prof. Derek Abbott has worked on this case for more than 2000 hours. [9] His team took the hairs from Somerton man’s plaster cast and recorded elements data by ICP-MS. Since 2009, it had become a final project for the University of Adelaide students and some students had participated this project. In 2013, the project group plot some Somerton man’s hair elements’ content figures and compared with control samples. [6] They have analysed the differences between Somerton man’s hair and control samples. However, those hairs’ data were all got from glass test. In this project, we redo the analysis based on the data that got from quartz test. In addition, we will compare those two different data figures. However, the new data should not be compared with old directly due to different drift values. The new data will multiply a constant which is got from the glass test remainder that is a bit rest of Somerton man’s unburned hair. Besides, the different year of plasters needed to be considered as well. 2.Software Hair data is recorded by Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and presented in the form of Excel tables. Matlab is used to plot figures which are used to show the elements comparison results clearly. It has some graphing capabilities and can be applied for making engineering plots.[3] In this project, the massive hair element data are plotted by Matlab command ‘scatter’. Then, use command ‘hold on’ to put the Somerton man’s and control samples hair data on the same figure and make the comparison clear. 3.Hair elements Hair analysis can demonstrate the content level of the heavy mental and essential elements in human body. [3] The different value of some essential elements in hair may be correlated with nutritional status and diseases, such as calcium (Ca), chromium (Cr), zinc (Zn), copper (Cu), and selenium (Se). The high values of some elements such as lead (Pb), arsenic (As), mercury (Hg), and cadmium (Cd) in hair can indicate the intoxicating phenomenon. [3] Using this analysis method can discover the useful information about the Somerton man healthy condition and has possibility to find the cause of death. 4. The relation between living environment and hair elements The living environment can affect the content level of elements in human body. This effect not only caused by polluted water and food, but through the injury and radiation. Trace elements values in hair can reflect the source of behaviors including the diet hobbies, smoking and medication. Human absorbs pollution source by different ways such as oral, breath, injection and radiation. These contaminants stored in different body organs and tissues can affect human health. Hair is a good indicator of environment change. Normally, it shows the variation of trace element in human body as the hair growth.

Glass test data analysis

Data screening

The hair data was recorded by mass spectrometer and the data was got from glass test. There are 44 elements gained by laser ablation (shown in Table 1). Three of these elements are needed to be mentioned. The first one is sulphur (S7) which must exist in human’s hair. The value of Sulfer can be refered to the drift value of the environment. The second one is lead (Pb206), the high level of Lead is harmful for human health. The third one is strontium (Sr88). This element has high percentage in Adelaide’s soil compared with other areas. So, the analysis of the change tendency of Strontium’s value will provide useful information about Somerton man’s living environment before his death. Table 1 Elements table for glass test

Table 1 Elements table for glass test