Who is telling the truth in Kate Reed Petty’s True Story?

This debut novel, which opens with ‘a high- school lacrosse party in 1999 and the rumour of a sexual assault,’ is billed as one story told in four different genres: memoir, horror, noir and thriller. It even has four covers. There is a reason for this, as Kate Reed Petty explains in an author’s note:

In borrowing these forms from popular culture, I was looking for ways to push against the simplistic assumptions we too often make about power, abuse and gender — assumptions that lock us into the same stories, again and again and again.