ThisLectureNotesinComputerScience(LNCS)volumecontainsthepapersp- sentedatthe ThirdInternationalWorkshoponComputationalForensics(IWCF 2009), held August 13-14, 2009 at The Netherlands Forensic Institute in The Hague, The Netherlands. Computational forensics is a research domain focusing on the investigation of forensic problems using computational methods. Its primary goal is the d- covery and advancement of forensic knowledge involving modeling, computer simulation, and computer-based analysis and recognition in studying and so- ing forensic problems. The Computational Forensics Workshop series is intended as a forum for researchers and practicioners in all areas of computational and forensic s- ences. This forum discusses current challenges in computer-assisted forensics and presents recent progress and advances. IWCF addressesa broadspectrum of forensicdisciplines fromcriminal inv- tigation. The NAS report "Strengthening Forensic Science in the United States: A Path Forward," published in 2009, already concluded that: "With the exc- tion of nuclear DNA analysis, no forensic method has been rigorously shown to havethecapacitytoconsistentlyandwithahighdegreeofcertaintydemonstrate aconnectionbetweenevidenceandspeci?cindividualorsource."Computational methods can assist with statistical methods using, for example, likelihood ratios to strengthen the di?erent ?elds of forensic science. The organization of such an event is not possible without the e?ort and the enthousiasm of everyone involved. We thank all the members of the P- gram Committee for the timely reviewing process and the adherence to high standards. June 2009 Zeno J.M.H. Geradts Katrin Y. Franke Cor J. Veenman IWCF2009 Organization IWCF2009 was jointly organized by The Netherlands Forensic Institute, The Hague, The Netherlands and the University of Amsterdam, Amsterdam, The Netherlands.