Btw, she is talking about Tsutomu Miyazaki, the "Otaku Killer" in that article

When police searched his home for evidence, along with the decomposing body of one of his victims, aged 5, they found thousands of child abuse and anime videos. Sociologists at the time argued his obsession with such illustrations encouraged him to act on his fantasies.

The thing is, said sociologists also blamed slasher films since the killer collected them too, that is in part why japan is so adverse to gore and dismemberments (Resident Evil is censored, Mortal Kombat is banned, etc).

Not to mention the background of mental issues he had, he was also a vampirist, necrophile and cannibal