Which of the following scenarios best illustrates the concept of specific deterrence?

The scenario where Franz decides to stop using drugs and earn his GED after serving six months in jail best illustrates the concept of specific deterrence. Specific deterrence refers to mechanisms that discourage an individual from committing crimes again based on their own experiences with the legal system or punishment. In this case, Franz's time in jail serves as a personal consequence for his actions, leading him to reflect on the negative outcomes of his behavior and change it. His decision to stop using drugs and seek education highlights how personal experience can lead to an individual's reform.

Other scenarios provided do not align as closely with the specific deterrence concept. For example, Frank stopping crime after witnessing his friend’s conviction speaks more to a vicarious influence rather than a personal consequence. Paul observing a failed robbery might suggest a shift in his perception of risk rather than a direct impact from personal experience, and a general fear of being caught does not implicate any specific consequence faced by the individual themselves, which is a key aspect of specific deterrence. In contrast, Franz's situation is rooted in his direct experience of punishment, making it the best illustration of this concept.