Police arrested a former graduate student of the University of Tokyo on Monday on suspicion of sending threatening letters and a cat carcass to an assistant professor of the university in charge who judged his master's thesis.
Now an employee of a patent company, Yasunari Kurita, 27, allegedly sent two threatening letters to the 42-year-old assistant professor, whose name is being withheld, between Jan. 5 and Jan. 17, police said.
In the letter, Kurita reportedly blamed the assistant professor for interfering in his personal life, and challenged him to a fight. Kurita received his master's degree in April.
The suspect, who lives in Kawasaki, is also believed to have sent the professor a dead cat in a box, and threatened to harm him. The professor claims he has done nothing to Kurita.