Marc Weber Tobias is an investigative attorney and security specialist living in Sioux Falls, South Dakota. He is the principal attorney for Investigative Law Offices, P.C. and as part of his practice represents and consults with lock manufacturers, government agencies and corporations in the U.S. and overseas regarding the design and bypass of locks and security systems. Marc and his associates also conduct technical fraud investigations and deal with related legal issues. Marc has authored five police textbooks, including Locks, Safes, and Security, which is recognized as a primary reference for law enforcement and security professionals worldwide. The second edition, a 1400 page two volume work, is utilized by criminal investigators, crime labs, locksmiths and those responsible for physical security. A ten-volume multimedia edition of his book (LSS+) is also available online.

Marc has written extensively about the security vulnerabilities of products and has appeared in numerous television and radio interviews and news reports as well as magazine articles during the past thirty years. He is a member of several professional organizations including the American Bar Association (ABA, American Society for Industrial Security (ASIS), Associated Locksmiths of America (ALOA), Association of Firearms and Tool mark Examiners (AFTE), American Polygraph Association (APA) and the American Police Polygraph Association (APPA).