The father of an 11-year-old boy murdered by a juvenile killer in Kobe in 1997 has issued a statement calling for rules banning perpetrators of serious crimes from publishing books related to their heinous activities.

Mamoru Hase, 60, whose son, Jun, was strangled and whose decapitated head was placed outside a school gate in the notorious murder case, released the statement to the media Tuesday, the 19th anniversary of his son’s death.

Hase expressed disgust over last year’s publication of a memoir by the perpetrator, who is now 33.

The memoir “was published with no notice to victims or bereaved families,” Hase said in his statement. “The book has aggravated the victims’ feelings and is an aggression by itself.”

Hase went on to say the issue is not about freedom of expression, but there should be regulations, if not an outright ban, barring criminals who try to publish books about their own crimes.

In the memoir, the killer, using the pseudonym Seito Sakakibara, called his crime against Jun Hase “a beauty.”

“Let me confess something: I thought the sight was a beauty,” he wrote in the book published in June 2015, recalling how he felt when he placed the boy’s severed head at the school gate. “I felt like I was born just to see the ethereal beauty of what was in front of my eyes. I thought I could die.”

Hase said he has rejected any correspondence from Sakakibara since the book was published, saying he doesn’t “want to have anything to do with him.”

“I vividly remember what happened on that day 19 years ago, like it was yesterday,” Hase wrote. “My love for my son hasn’t changed.”

The killer was 14 at the time of his crimes. He killed two children — Jun Hase and a 10-year-old girl, Ayaka Yamashita — and attacked three other schoolgirls.