What are the patterns of mystery novels?

The mode of nursery rhymes killing and prophetic killing has to be mentioned again. The murderer continued to kill people according to nursery rhymes and predictions. This nursery rhyme is equivalent to the script outline of his serial killings. The variation is that imitators continue to kill people according to this outline, and there are many murderers. The variant mode is preview killing, but the difference is that nursery rhyme killing is often found after the murder, while preview killing is found before the murder.