Context and motivation: Design Thinking techniques have been widely used in the elicitation of software requirements, since such methods obtain satisfying results when applied to understand the necessities of both stakeholders and end-users. However, there is a lack of evidence on their effectiveness when applied to populations considered vulnerable. Question/problem: What are the implications of using Design Thinking techniques to elicit requirements in a community of former inmates - and what would be the benefits of and challenges in this deployment? Principal ideas/results: In this paper, we report our experience on using Design Thinking for Requirements Elicitation of a mobile application, customized for a vulnerable population: the former inmates of the Brazilian Prison System and their families. Research approach and methodology: We utilized the d.school Design Thinking method during our research. Techniques such as Brainstorming, Stakeholder Mapping, Personas Creation, Rapid Ethnography, and Interviews were used to obtain relevant data. Furthermore, during the development process, several prototypes were created. Contribution: The use of these techniques generated important contributions for the development of an uncommon application that aims to help the reintegration process of former inmates into society. The results obtained validate the initial hypothesis that such techniques, even when applied to a sensitive context such as this one, assist in the development of a product that meets the needs of the end-users by creating a higher quality product. Limitations of results: The main limitation of the research was the lack of access to low literacy end-users and/or former inmates without previous experience using mobile devices.