Detective Nakagawa: It is said in Japan that when a person dies in extreme sorrow or rage, the emotion remains, becoming a stain upon that place. Death becomes a part of that place, killing everything it touches. Once you have become a part of it, it will never let you go.
Detective Nakagawa: Three years ago, three of my colleagues were investigating what happened in that house. Two died mysteriously. The third was never found.
Kayako Saeki: Croakkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk.
Karen: There is something evil there.
Karen: The whole time I was in that house I felt something was wrong. What happened there?
Answer: Kayako was murdered by her husband when he found out that she has romantic feelings for another man, since this would be a crime of passion driven by hatred the cutting out her face from all the photos then sinisterly pinning them to the door is another sign of his hatred. Like him removing her from the family and cause futher pain with the needles. Also to display her face would most likely be a way of shaming her further, insult to injury and all that.