During the day, Miyazaki was, by all accounts, a mild-mannered individual. Outside of work, he randomly selected children to kill. He wrote to the families of his victims, sending them letters recalling the details of his murders. Police found that the families of the victims had something else in common: all received silent nuisance phone calls. Miyazaki would not speak a word during these calls, instead simply breathing heavily. If they did not answer Miyazaki's calls, he would call repeatedly; sometimes their phones would ring up to 20 minutes.