A Question

From the back of Velocity, by Dean Koontz, comes an idea for a question. (And, yes, I had to buy the book.)

Suppose someone left you a note that said this:

"If you don't take this note to the police and get them involved, I will kill a lovely blond schoolteacher somewhere in Napa County. If you do take this note to the police, I will instead kill an elderly woman active in charity work. You have six hours to decide. The choice is yours."

What would you decide to do? Who dies?