Make your choices carefully and try to figure out who the killer is based on the few obscure clues. Remember, if something seems suspicious... it's probably worthy of suspicion, and caution too.

An additional note: after you're done with one character, you can come back and play the others! Each scenario's different. You can get to know all six main characters and see things from their eyes. None of the stories has the same killer or killers, or the same first victim. The original victim is a subtle psychological hint of the killer's identity. It's not always a main character who did it, and it's not always just one person. The only constant is the fact that the villain is the same in each story. The choices you make don't change who the killer is.

One last thing before you start: a helpful hint or two.
Take a careful glance at your selected character's profile before playing. Each person has their own strengths, and those traits make a difference as to whether or they'll succeed in trying to perform certain actions. Like, say Rachel and Will are fighting the killer. Will's a big, tall hulk of a muscled football player and Rachel is of slightly over medium height, slender and willowy. So in a session of unarmed combat, Will could take an anvil to the head (well, not a real anvil, but a heavy blow) and hardly feel a thing, whereas the same blow would be likely to knock Rachel out cold. However, Rachel's smaller build and greater awareness of her surroundings make her harder to hit in the first place, whereas Will might as well have a bull's-eye tattooed on his chest. Also, Rachel is naturally intelligent and alert, so that makes her more likely to figure out the killer's identity beforehand, lessening the element of surprise. She would probably be more coolheaded in a fight. So, the point is, each character has their own style and their own advantages--work with them. Remember this tip when deciding whether to take the punch and swing back or duck, dodge, and run away. This applies to certain horror movie stereotypes as well--if you're a quiet, thoughtful brunette virgin, you're less likely to die in any given situation than your perky blond-haired promiscuous cheerleader friend.

Oh--one last hint--when you're in a sticky situation, try using your masculine/feminine wiles. Sometimes they're all you have to fall back on.