Columbine

Copyright

Copyright (c) 2009 by Dave Cullen

All rights reserved. Except as permitted under the U.S. Copyright Act of 1976, no part of this publication may be reproduced, distributed, or transmitted in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher.

Twelve

Hachette Book Group

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New York, NY 10017

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Twelve is an imprint of Grand Central Publishing.

The Twelve name and logo are trademarks of Hachette Book Group, Inc.

First eBook Edition: April 2009

The characteristics of psychopathy are from the Hare Psychopathy Checklist—Revised (PCL-R; 1991, 2003). Copyright (c) 1991 by R. D. Hare and Multi-Health Systems, 3770 Victoria Park Avenue, Toronto, Ontario M2H 3M6. All rights reserved.

ISBN: 978-0-446-55221-9