It was a book I read as a kid. It was a lois Duncan style book and was titled something similar to I know who killed me. A girl starts getting the urge to cut her hair a certain way, similar to a girl that was murdered it triggers the murderer to stalk and attempt to murder her as she is driven with guilt by the protagonists growing similarities to their victim. I believe she tries to drown her in a lake.
by GibbGibb