The topic that prisoners who became good citizens later are giving a talk to students has been a cause of concern for some time. According to some people, this is the best approach to persuade them to not commit a crime. Although this option can be useful in some cases, I reckon other good ways to tell them about the danger consequences have better potential in efficiency and convincingness.
On the one hand, there are several obvious advantages of this option. First and foremost, storytelling from experienced and knowledgeable people sounds more convincing. In other words, students are more likely to believe real stories with true evidence and arguments. For example, in Stanford University there was a study where psychologists identified that 82% of middle school students believed sponsored content with real news stories . Because students evaluate information based on how professional it looks, rather than the actual source. As a result, undoubtedly this way to tell them about danger after doing illegal actions is more effective with the ex-prisoners, rather than with the general people.
On the other hand, there are a lot of other ways to do it. The most obvious is state intervention, where the government can invest in youth and social programs to prevent early crime. In other words, talks with ex-prisoners are mainly based on fear, which does not solve the real causes of early crime such as poor conditions, peer pressure and boredom. For instance, local communities can provide free sport spots or psychology clubs for teenagers. Since these activities will keep them busy, there will be no time to commit a crime. As a consequence, this approach can effectively reduce youth crime rate in the long term.
In conclusion, although providing a talk between students and prisoners can warn them about a prison, this is not the best solution. Investing in social programs provides much more effective and long term approach.