From the latest investigative techniques to “certain words” that appear frequently in cases… Unraveling the police “jargon” that appeared frequently in ’25

A new crime term called “Tokuryu” is also gaining citizenship these days. In line with changes in crime forms, the police are also introducing new investigation methods. Nonfiction writer Masahiro Ojima explains various “technical terms” reported in the news in 2013, based on actual cases, in order to deepen your understanding of the news.

New crimes in focus in ’25

In recent years, there has been a series of robberies and other crimes led by an instructor, in which the perpetrator was recruited by offering a large sum of money for a part-time job through highly secretive communication applications on smartphones such as Telegram and Signal. Newspapers and TV news repeatedly reported that the incidents were committed by “Tokuryu,” which stands for “anonymous and fluid crime group. Nowadays, the word “Tokuryu” brings to mind a series of incidents, and it seems to have become firmly established in society and, for better or worse, has acquired a sense of citizenship.

The police authorities have positioned Tokuryu as “a group of people who repeatedly disperse through loose ties, such as black market jobs recruited through social networking services. The group includes not only robbers and other violent criminals, but also special scams, romance scams, and investment scams, which have been rampant in recent years. In addition, the law also recognizes as a “Tokyru” any method that uses “highly confidential communication applications,” such as malicious scouts who receive high rewards for introducing women to brothels.

How are the police authorities investigating the exchange of information through “Telegram” and “Signal,” highly confidential smartphone communication apps? The word “digital forensic investigation” was widely reported.

For example, in a robbery and murder case in ’23 committed by an instructor and others who called themselves “Ralphie” and others, the Joint Task Force first seized a significant number of smartphones from searches of those used by the perpetrators and related parties. Although the messages on the phones were encrypted, an investigation was conducted to discover and recover faint traces of the message exchanges by using special software. This was a “digital forensic investigation.

The messages were pieced together to revive the communication between the instructor and the perpetrator. We sucked up the fragments of data that had not been completely erased and pieced them together. We didn’t miss the slightest mistake by the criminal group in the black market case” (a senior police official).

He also reveals the following behind-the-scenes details of the investigation.

The number of black-market crime cases, such as serial robberies, stopped after the end of 1949. During that period, several hundred people were arrested nationwide for cases involving special fraud groups, malicious hosts, scouts, and others. It was believed that because some of these people were directing the black market cases, the instructions for robberies and other crimes had ceased and the outbreaks themselves had ceased. As predicted, we are beginning to be able to bring the directing officers out of the arrests and into the line of investigation.”

A Word” reported for a blunder inside the police department

When a criminal is brought to the forefront of the line of investigation during the course of an investigation into a case, investigations such as “behavior confirmation,” literally, “behavior confirmation,” are conducted to confirm the behavior of the criminal by following him or her and conducting stakeouts in order to understand his or her daily patterns of behavior. The word “kokaku ” for short is used by detectives in the field. A detective who is engaged in on-site investigations explains.

First, we check the yasa (address or place of residence), and if there is a place of employment, we ascertain whether the person commutes to work every day and what his or her main place of residence is after leaving work. If he/she does not have a regular job, ascertain what his/her daily activity pattern is. We can’t afford not to know where the person is if we obtain an arrest warrant.

There have been cases in which words such as “koukaku” have been widely reported.’ In January 2013, the Anti-Organized Crime Division of the Tokyo Metropolitan Police Department (Anti-Organized Crime Division) moved to arrest the leaders of the malicious scout group “Natural,” but just before the “X-Day,” all of the members disappeared.

In November, a police lieutenant in his 40s from the Metropolitan Police Department’s Anti-Violence Division was arrested on suspicion of violating the Local Public Service Act (duty of confidentiality) by leaking information to “Natural” about this fiasco. Newspapers reported on this arrest, with a senior Metropolitan Police Department official commenting, “We were koukaku-ing the person we were going to arrest, but he disappeared all together. The police department’s official comment on the arrest was, “We had been koukaku-ing people we were going to arrest, but they disappeared all at once.

The word “Special Investigation Division” was also frequently reported in newspapers and TV news since the fall of ’25. In order to strengthen the crackdown on Tokuryu, the Metropolitan Police Department merged the Criminal Investigation Department and the Organized Crime Department into a new Criminal Investigation Department on October 1, and established a new Special Investigation Section with approximately 450 personnel to specialize in Tokuryu investigations.

New investigative methods were also introduced. A “disguised identity investigation” was introduced, in which investigators apply for black market jobs on social networking sites, pretend to be hired, and contact Tokuryu. The department has a track record of arrests on fraud charges in special fraud investigations. In recent years, it has been discovered that special fraud callers are based in Southeast Asia, including Cambodia, so cooperation with police authorities in other countries is essential.

Words with “maru” often heard in dramas

Lastly, I would like to introduce a few words that are not words used in news reports, but rather cryptic words that are used daily by detectives in the field in the police community.

In the police department, various terms are often used with “maru” attached to them. The word “suspect,” used for a person who has been arrested, is a news term, and the police refer to him or her as a suspect. Therefore, the suspect is referred to as “Maruha” by adding a “Maru” to the “Hada” (被). The victim of a crime is called “Maru-harm “, and those who are the subject of an investigation, including witnesses and related persons, are called “Maru-tsu”. A body that has died a strange death is called “Maru-hen. There are many other examples of the term “Maru…”.

Among these cloak-and-dagger terms, there is one that is used in a manner completely opposite to its original meaning. It is the term “Marubori. A veteran detective who has been involved in gang crime investigations for many years explains.

A veteran detective who has been investigating gang crimes for many years explains, “In the past, gang members themselves were called ‘maruboryoku. Gradually, detectives who investigate cases involving gang members came to be called “maruboryo detectives.

I have heard that the word “detective” was simplified from “Marubori detective,” and detectives specializing in yakuza investigations came to be called simply “Marubori. This was a long time ago, so I don’t know when or why.

Criminal methods continue to change and become more complex as society changes. We urge you to keep these words in mind for a deeper and correct understanding of the many news stories.