The objective of this article is to present a study of two observers turning into whistleblowers through stages of crime signal detection, registration, interpretation, reception, and knowledge. The study applies signal detection theory emphasizing signal alertness, signal reflection, pattern recognition, and personal knowledge. The research method applied is personal interviews with the whistleblowers who noticed deviant behavior, one of which blew the whistle on corruption that later led to the incarceration of several corporate executives. Results indicate that the whistleblowers became more certain of their information as they could discuss their observations with others. An important human factor in whistleblowing is thus the ability to discuss initial observations with people that one can trust, which can lead to documented allegations against suspected individuals. The case studies illustrate experience from troublesome whistleblowing on top executives, where the second whistleblower was less successful.