Britain’smostnotoriousserialkiller, DennisNilsen, confessedtokilling15peoplein1983.Overafive-yearperiod, hepickedupvulnerableyoungmen, luredthembacktohishomeandstrangledthem, beforedisposingoftheirbodiesunderthefloorboards.Thetruthabouthowandwhyhekilledhasbeenthesubjectofmuchspeculationinbooksanddoc...