Teen arrested over possession of high explosives

First of all, I decided to start writing short reviews of the Japan Times Alpha, a news article for English learners every day.

Police arrested an 18-year-old high school student for possessing explosives.
One of the explosives, triacetone triperoxide (TATP), is commonly used in terror attacks because it can be produced using ingredients that we can access easily.

The main reason for these crimes tends to be from their own beliefs.
Japan is a great country to the point that people are able to have their own opinions and beliefs. However, on the other hand, it can make crime that is the reason for their beliefs. So I think the most important thing to solve and prevent such crimes from happening again is figuring out the reason why they did it.