This guide, updated in 2006, sets out the basics for investigators in prosecutors’ offices and other law enforcement personnel. Topics include: (1) investigative techniques (including crime scene search; collection of evidence; DNA evidence; fingerprints; blood spatter); (2) information sources (including municipal, county, and state government; commercial sources; directories; national agencies); (3) evidence (such as demonstrative evidence; character evidence; opinion evidence; confessions); (4) forms (including confession worksheets; laboratory requests; criminal history requests); and (5) administrative forms (including case work-ups; witness letters and forms; pen packets). Editor A.P. Merillat is an investigator in the Special Prosecution Unit in Huntsville and author of “Future Danger (The Final Word in Capital Murder Prosecutions).”