The Reference Manual on Scientific Evidence, Third Edition has recently been released by the National Academies Press. This work is a substantial update to the prior version, which was first published in 2000, and is intended as a guide to the federal judiciary in assessing complex scientific, economic and engineering issues. In addition to revisions to existing chapters there are four new sections on Forensic Identification Expertise, Exposure Science, Neuroscience, and Mental Health. Of special interest is the new Reference Guide on Exposure Science, which is meant to compliment the sections on epidemiology and toxicology by describing the methods used in estimating the dose of a potentially toxic material to which persons may have been exposed. The newly drafted section on Neuroscience covers the use of neuroimaging or scans to assess an individuals claims concerning pain, and in the context of a criminal proceeding diminished capacity, sanity and honesty. The Third Edition may be purchased form National Academies Press or a free PDF version downloaded at their website (registration required).