I need help with the choices.

So the day before the 4th July party, we all gather for Greer to announce her secret about the story right? In the conversation, its bought out that I was called for questioning and I choose to share a bit of the truth ie I blacked out. Now the family wants to know who I think is the killer... Who do I choose? This is my first play....so im very confused and cautious of the choices..