You've been handed an investigation, an interview or a risk assessment, and no one ever taught you the method.
A. Hertzog writes for the security manager, the investigator and the professional who has to get the work right on Monday morning, not admire theory. Step by step, built on real cases (his own mistakes and other people's) and on one discipline: document well, then decide.
Hertzog served in the U.S. Marine Corps, worked in law enforcement and holds a Bachelor's in Criminal Justice. He writes the way he works: method, evidence, judgment.
Start with the book that solves today's problem.