Instead of plotting ahead of time, I let my characters control what happens. They show me who the suspects are, when things happen, why they fight, and ultimately who did each crime. While I know this method is not for everyone, it is what works for me. I feel that the story is more organic, more real, this way. Sometimes, when you plot things out ahead of time, things can feel forced. A character may do something that is unnatural for them because the outline says they have to. A big plot point may be revealed to early or too late. With pantsing everything happens when the character needs it to happen. Since the characters themselves are controlling things nothing feels out of place.
There are, of course, problems with this method. One of those is length. Sometimes my characters finish the story well before it is long enough to be considered a novel, other times they take too long. They also occasionally do things you don’t want them to do. For example, in my latest work-in-progress I had intended my main character and her boyfriend to break up. They had their fight, but somehow the boyfriend refused to get mad at her. While I do think that this was the right thing for the characters in the end, it was very frustrating in the moment.
Overall I know that pantsing is the right method for me. I love the surprise involved, for me as well as the reader. It is harder, though not impossible, for the reader to figure out the killer if I don’t know myself! I also enjoy the freedom that pantsing gives. There is nothing, save for finding the killer, which HAS to happen in any story I write. While there is certainly struggle, I know that this is the method for me. Maybe it is for you as well.