Many people might still remember the “Wakayama Curry-Poisoning Case” in 1998.　However, the fact has been forgotten that in order to identify the suspect in the case, a scientific criminal investigation utilizing the then world's most advanced science technology was conducted.　An X-ray analytical technique was introduced into the scientific criminal investigation, which analyzed that the “arsenious acid” that was mixed in the curry was the same as the “arsenious acid” that the suspect had had. X-rays are invisible electromagnetic waves and also a type of light that has an atom-sized wavelength. Just like when you see an object under the light, if the luminance is very high, you can detect (see) even a “minute amount of samples.”

As one type of X-ray, the “radiated light,” the most-advanced light whose luminance is one billion times higher than that of natural sunlight, and that was created in the world’s largest synchrotron radiation facility “SPring-8” that had been newly built in Harima Science Garden City, was used. This “radiated light” is a type of X-ray with a high luminance that appears when you accelerate electrons to the speed of light, applying the same principle used in the large “accelerating device” that detected the existence of the Higgs boson, and change their direction by using a strong electric magnet. This “radiated light, “high luminance X-ray,” broke the limit of “minute sample” detection.

Since then to 2010, ‘radiated light’ was used in solving forty-two major cases. (Statistics by the Metropolitan Police Department). During that time, “radiated light” technology has shown rapid progress to the point of developing a technology that enables to concentrate a light beam to the size of 100 nm (nm: A nanometer is one millionth of a millimeter.), which has been shared among researchers since 2011. This leading-edge optical technology that has been utilized in various fields, such as physics, science, material science, nanotechnology, environmental science, life science, in addition to its feature “minute sample” detection, has made it possible to conduct an analysis at the nano-level of a microscopic area, which is going to bring the “nano innovation” into the scientific criminal investigation. At SPring-8, the Nano Forensic Science group was established in the Public Interest Incorporated Foundation, Japan Synchrotron Radiation Research Institute, in December of 2011, with the aim of promoting the utilization of advanced measuring technology by “radiated light” in the scientific criminal investigation.

Beginning of the modern scientific criminal investigation brought in by X-rays

The discovery of ABO blood groups by Landsteiner (1901) is often pointed out as what marked the beginning of scientific criminal investigation. However, it must have been the discovery of X-rays that had the most powerful impact on the scientific criminal investigation and paved a new path.

On November 8th of 1985, Roentgen discovered the new light “X-rays” and showed X-ray pictures of bones in human hands and the marking of a mariner’s compass or the compass needle pointing in a certain direction placed in a metal case, thus he demonstrated that the inside of an object could be seen through in a non-destructive manner by utilizing X-rays. This technique drew attention as being a revolutionary scientific criminal investigation method in those days, and the technique was used within a few months after its discovery to identify bullets in a human body involved in a suspected gun-related murder case in England. It is reported; however, it took more than 60 to 70 minutes to take one X-ray picture in this case.

On the other hand, the property of X-rays has also been applied in fundamental science, such as in architectural analysis for clarifying the atomic arrangement in a substance by means of X-rays, the development of a fluorescent X-ray analysis method for studying what element constitutes a specific substance, and an X-ray computed tomography technique that is now being widely utilized in medicine for examining a nidus. The double-helical structure of DNA, which is the foundation of life science, was also revealed by X-ray structural analysis in 1953. A “DNA test,” which is utilized for individual identification where a minimum amount of DNA type substance is amplified to a maximum extent by utilizing this characteristic double-helical structure of DNA, is serving as an extremely powerful measure in scientific criminal investigation methods today.

As mentioned above, the accumulation of X-ray-related achievements in fundamental science, which has also contributed to a number of scientists winning Nobel Prizes, serves as a foundation for scientific criminal investigation in various ways today.

“Radiated light” and nano forensic science

It was the emergence of “radiated light” that brought an innovation to X-rays. And it is SPring-8 that succeeded in proving the usefulness of “radiated light” in the scientific criminal investigation. This SPring-8 was built as the world’s largest synchrotron radiation facility in one corner of the Harima Science Garden City in Hyogo Prefecture in 1997. The facility was built in such a mountainous place, because that immense area, which is supported by a solid and huge slab of rock, was thought to provide the perfect foundation that would become essential to creating nano-scaled X-ray beams in the future.

In the “Wakayama Curry-Poisoning Case” which occurred in the earliest days of the facility, a lot of attention was paid only to “high luminance X-rays,” however, the technology to constantly generate nano-scaled “radiated light” beams was finally established 15 years after that. Nowadays, the industrial use of SPring-8 has extended to the area where advanced technology is directly adopted to product development, such as in developing the fuel-efficient tires “Enasave” produced by Sumitomo Rubber Industries, Ltd. and brought out at the Tokyo Motor Show in December of 2011, without being restricted to the analysis for materials evaluation or quality assurance. Additionally, an X-ray free electron laser facility “SACLA” was adjacently built with the aim of promoting the National Critical Technology and it has been operating with SPring-8 since March of 2012 as the world’s second facility that can generate an X-ray laser that has a luminance almost one billion times higher than that of SPring-8.

However, compared with the fact that SPring-8 is used in about 2,000 research projects every year, you certainly could not say that it is fully used for the scientific criminal investigation. It is partly because SPring-8 itself is such an extremely large facility that it cannot be built within the facility of the investigation agency of each prefectural police department. Therefore, the powerful properties of the “radiated light” that SPring-8 gives off and its innovative technology have not been fully shared between persons related to investigations and scientists in terms of meeting the needs of the scientific criminal investigation.

In response to this, the nano forensic science group started with the aim of developing the method in which advanced technology relating to “radiated light” can be used to meet the specific needs of the scientific criminal investigation and promoting the use of “radiated light” as the “light to uncover the truth.” “Forensic Science” is translated into Japanese as “Ho Kagaku (法科学),” which generally has a broader meaning than the scientific criminal investigation by the police, and it has already been well-established in the West as a “learning that includes any type of science associated with trials (laws).” This group, taking advantage of the characteristics of “radiated light,” cooperates with persons involved in criminal investigation, for example, by sharing the application of “radiated light” where the truth is able to be detected even from a 100 nm-sized microscopic article of evidence, with the aim of developing a new method of observing and analyzing evidentiary materials and uncovering the truth with a “nano ruler” which is 1,000 times smaller than a conventional “micro ruler.” In addition, the group is going to establish the utility institution of “radiated light” in scientific criminal investigation and the standardization relating to the accuracy and reliability of nano scales in detecting ability.

Judicial reform and international contributions

One of the factors that led to the founding of the group was judicial reform. The lay judge system that makes citizens take part in rendering a judgment was introduced in 2011, and around the time of the establishment of this new system, in 2010, the statute of limitations of major heinous crimes was abolished or extended by Act No. 26. With this, reexamining properties or materials left behind relating to unsolved major heinous crimes has been considered. Since conventional analysis methods could not find solutions for crimes, consequently, it is required to utilize more advanced science technology, etc. in investigating methods.

In this situation, as a pivotal agency, it is very important for SPring-8 to play a key role in proceeding with the technological development of forensic science technology relating to criminal cases, which has been mainly done by the research institutes of investigation agencies, to cultivate this area into the field of nano forensic science utilizing “radiated light,” and standardize this technology so that it can be effectively shared in criminal practices. Additionally, the development of international contributions, without being limited in Japan, is now being discussed, which involves its working on problems that need global cooperation, such as the prevention or eradication of drug abuse etc. In this way, “radiated light” created by SPring-8 has already started to be utilized for solving the issue of “constructing a safe and secure society.”

Chinese / Japanese