Twenty-one organizations promoting volunteering in Portugal were contacted to carry out this study, of which fourteen agreed to participate. These organizations were located in the cities of Coimbra (n = 1), Lisbon (n = 8), and Porto (n = 5), and were selected based on their involvement in prison-based volunteering programmes (Figure 1).

The researcher (MS) contacted the representatives of the volunteering associations, providing them with information about the investigators, the purpose of this study, a brief description of the methods used and contact details for possible questions or concerns that could arise later. The participant information sheet with additional details about the study was sent via email to the respective representatives of each association, as well as a letter of support for the dissemination of the project to the volunteers of each association. It should be noted that until the time of the interviews, the authors did not know any of the participants. The only inclusion criterion considered was that the participants had volunteered in prisons (i.e., had participated in some activity or volunteering program with prisoners).

For this study, the semi-structured interview guide from Kort-Butler & Malone, 2014 (13) was translated into Portuguese, adapted and used to assist the interviews (Appendix 1). The researcher (MS) conducted the individual semi-structured interviews exploring the motivations that led to the involvement of participants in volunteering in prisons, the interactions that the volunteers established with the inmates and with the prison staff, and the impact of volunteers in the inmates and on themselves. Sociodemographic information was also collected (Appendix 2).

Due to the Covid pandemic, interviews were primarily planned to take place remotely or where possible, in person. The interviews were conducted by a female researcher (MS) and took place in a quiet location chosen by the participants. The data was analyzed through thematic analysis as outlined by Braun and Clarke (22) with the assistance of the QSR International Nvivo 12 software. The names of the volunteers were eliminated and replaced by numbers in order to protect their privacy. The initial codes were later organized and placed into themes. The themes were based on the scientific question, were again revised, and organized by the researchers (MS, who has a degree in criminology and MPC, who is a psychiatrist). The interviews were conducted in Portuguese, as well as the data analysis (Appendix 3). The sub-themes and themes as well as the quotes were translated into English by the researchers to be reported in this publication. The COREQ guidelines were followed for the study reporting (Appendix 4).

The volunteers described different reasons to become involved in volunteering in prisons (Table 2). Most volunteers had previous experience with other types of volunteering, although some volunteers chose to start volunteering in prisons to occupy their free time. Reasons ranged from religious faith, the need to help others, a recommendation made by someone, or the opportunity to volunteer in a prison, perceiving it as a way to get out of their comfort zone.

Volunteers said that after retiring, they had more free time, and began volunteering as an option to occupy them.

Religious belief was a common motivation for volunteering. However, volunteers stated that they did not go to visit prisoners in order to impose their beliefs and values on the inmates, but to aid inmates whilst following prison rules.

Volunteers described a commitment to society and a need to help the inmates. Throughout the interviews volunteers showed great concern for the prisoners.

Previous experience of volunteering was common among volunteers. This involvement in volunteering led volunteers to be willing to continue their role as volunteers in settings or populations with whom they did not have experience before, such as in a prison context.

The involvement in volunteering in the prison context for some volunteers emerged from recommendations made by friends or family or their mentor, either through knowledge of the associations, or through their own experience in volunteering.

Uncommonness contributes significantly to the lack of public awareness of prison volunteering opportunities. Some volunteers report that they had no prior intentions of volunteering in a prison. However, when this opportunity to volunteer in a prison emerged, volunteers appreciated leaving their comfort zone.

By volunteering in a prison context, volunteers gain new perspectives through their interactions with inmates and the relationships they develop with them. This relationship had a positive evolution as volunteers maintain a repeated and constant presence, being able to communicate with prisoners without prejudice or judgement (Table 3).

The relationship that volunteers developed with prisoners is mostly positive. However, volunteers described the need to resort to conversation unblockers to break the ice as a way to start talking to the inmates and gain their confidence. Volunteers described individual characteristics that they deemed volunteers should have to reach out to inmates, such as the ability to listen, honesty, sincerity, equal treatment and the ability not to judge. Volunteers considered that having an open and unprejudiced attitude toward inmates facilitated these interactions.

As in any other context, to create some kind of relationship it is necessary to build trust, which cannot be done overnight. With the prison population, the care and time taken to gain confidence is different, as inmates tend to be naturally suspicious.

Volunteers presence in the prisons becomes frequent, which means that as the conversations gain more weight and the trust is built, the inmates end up mentioning life situations that they do not mention with their cellmates.

Some prisoners are allowed by the prison director to go outside the prison for a short period of time. During this period, and in certain situations, inmates may be accompanied by volunteers. In these cases, this monitoring is often done with the same inmates for some time, contributing to the establishment of a positive interaction between volunteers and inmates outside the prison.

In addition to the contact that volunteers have with inmates throughout their voluntary work, they also gain knowledge about the prison system itself through the relationship they create with prison staff (Table 4).

Before there is any interaction with the inmates, volunteers must have contact with prison guards, particularly when entering and leaving the prison. This first contact was not always positively described. At an early stage, volunteers described this interaction as cold, with some suspiciousness from prison guards, who were distant and sometimes even posed obstacles to volunteers when entering in the prison establishment.

At the beginning, due to the distance that the guards kept from the volunteers and the strangeness of their presence in the prison, some volunteers said that they felt perceived as obstacles by the prison guards. They also felt that they could be hindering the work performed by the prison guards themselves.

The interactions between volunteers and prison guards evolved over time, and the initial problems mentioned no longer existed. Volunteers stated that after the first volunteering sessions, the prison guards became more accessible, increasingly trusting the volunteers, being positive in their interactions, and treating them with cordiality and mutual respect and, that they were more satisfied and committed to continue volunteering.

Volunteers described the environment within the prison as hard. The structure and buildings of prison establishments are old, and they have few conditions for proper spaces adequate for volunteering activities.

Although contact in the prison was mostly between the inmates and prison guards, the volunteers also maintained contact with the volunteer managers, the technicians who oversee the volunteering work, although less frequently. This interaction established with the volunteer managers was described as very positive with the technicians showing themselves to be quite accessible to the volunteers.

Volunteering in a prison context is a less known reality in the general population in Portugal. However, as the contact with this reality increases and, consequently, the contact with the inmate population, the impact that this volunteering causes in the lives of volunteers increases (Table 5).

The contact with other realities different from the one that the volunteers lived in made them gain other perspectives. They described realizing that there are other realities outside their professional and personal environment that, until they had contact with the inmates and heard their stories, they were unaware of.

Volunteers said that managing their own expectations was one of their biggest challenges. They recognized that they could only help in very few things because the inmate's reality does not depend on the volunteers.

With the experience of volunteering in a prison context, the volunteers said that they ended up relativizing certain problems. This relativization led them, in a way, to reformulate their priorities, not taking things for granted in their own lives.

Volunteers perceived volunteering in prisons as something positive in the lives of inmates, bringing them various benefits (Table 6).

Volunteers mentioned the importance of volunteering programs and activities, as these programs aim to teach inmates skills that could be useful for them in the future.

To combat the routines in prison, these interactions with volunteers provide new opportunities, new routines, and new schedules because the inmates are already counting on activities or visits on those days.

Volunteers end up being the contact between inmates and the outside world, particularly with families. Whenever possible and with the knowledge of the prison's management, volunteers could contact the inmates' families and even help with transporting so that families could visit their inmates in prison. Inmates are not always in a prison establishment close to their residence area, which sometimes makes it difficult for families to bear the costs of long journeys.

The regular presence of volunteers in front of inmates contributes to the continued existence of social bonds despite inmates' confinement. Through visits and activities, volunteers end up having time with the inmates, where they can speak openly and without judgment, promoting communication and combating the isolation of inmates.

Volunteers made some recommendations to improve the reality of volunteering in a prison context. These suggestions focus especially on maintaining a demanding training programme. Furthermore, volunteers also suggested that volunteering in this context be considered as a form of reintegration into society that can go beyond the prison establishment (Table 7).

Volunteers mentioned the importance of having detailed and ongoing training before entering the prison. Almost all volunteers received training before starting volunteering inside the prison establishment. In this setting, it is necessary to bear in mind the rules that exist and, to avoid future problems, volunteers should be mindful, aware, and prepared to possible situations that might happen so that they know how to deal with them in the best way.

Volunteers considered that there should be a careful selection of volunteers with the necessary characteristics for someone to volunteer in a prison and to be able to communicate with the inmates. Prisons were described as a difficult and heavy environment, not everyone has the necessary qualities, nor can they adapt to the prison environment.

Volunteers referred to the improvement of conditions in places where volunteering activities take place. Prison establishments are normally places with a hostile environment and, to facilitate this volunteering, a favorable atmosphere should be created during these activities for inmates to abstract.

Volunteers mentioned the importance of having a good relationship between volunteering associations and prison establishments so that the surrounding environment is one of union and organization. Besides, the relationship among the volunteering associations themselves is always important, facilitating dialogue and cooperation between them.

Volunteers recommended volunteering as a form of reintegration for inmates in the prison, but also to extend volunteering beyond the prison context to the moment of departure. Some volunteers supported greater contact with the prison population as a way to reduce the stigma associated with inmates and normalize their reality.

Volunteers emphasized the importance of adequate training in the preparation for volunteering in prisons, and that the volunteers should be carefully selected. Without this, boundaries can be unclearly defined, potentially leading to problems such as the emotional involvement with an inmate, manipulation or even loaning money.

The importance of the activities that are carried out with the inmates was also highlighted, since these are aiming to support prisoners to gain skills and competencies that will be useful for their reintegration process outside prison, to stimulate a process of introspection and establish short, medium, and long-term goals.

Volunteers perceive their role as impactful in the inmates, but also in the surrounding prison environment. After gaining the inmates' trust, it was possible for inmates to talk about matters with the volunteers that they would not want to talk to cellmates.

As far as we know, this is the first study in Portugal on volunteering in prisons. The study covered multiple areas: volunteers' motivations, the interactions that volunteers established with inmates and with professional staff, and the impact that this volunteering had on the lives of volunteers. Therefore, these findings add to a very limited literature base and hopefully set grounds for further work. The geographic coverage of this study is also a strength, as the volunteers belong to the main cities in Portugal providing us rich and detailed information about the phenomena.

The study has however some limitations. Firstly, the sample covers primarily volunteering associations based in urban areas and not in rural areas. Secondly, the volunteers were not directly asked if at any time they served a sentence in a prison or if they had a family member who has been incarcerated, which limits the understanding of the characteristics of these volunteers, and how individual factors may play a role in their motivation to volunteer in the prison setting. Finally, the perspectives in this study were only based on the volunteers' perspectives, and therefore the perception of inmates of these same interactions has not been investigated in this study.

In our study, volunteers in the prison context in Portugal showed a very positive attitude toward inmates, demonstrating an easy attitude in their presence, without fear. This positive attitude toward inmates has also been found in research in other countries such as with volunteers in Canada, where the outcomes of a voluntary visits programme focusing on benefits to inmates, volunteers and prison staff were positive (16). Volunteering visits were beneficial not only for inmates, since these gave them the opportunity to talk safely and adopt a more optimistic view of the future, but also for the volunteers themselves since they felt more appreciative of their own quality of life (12, 16).

In this study, volunteers in prisons were mostly motivated by the greater availability and time in their lives, past experiences, and the need to help others. These same motivations were described in other research conducted in Southern states in the USA, where volunteers expressed their personal beliefs as one of the reasons for volunteering, sharing their blessing and values to the inmates, the commitment they felt toward volunteering and toward the volunteers themselves also contributed to their involvement in volunteering in the prison context (13, 23). Similarly, another study conducted in the state of Minnesota in the USA acknowledged that when it comes to volunteering, volunteers feel the need to help others and express their values and beliefs as a way to show their concern with others (24). Likewise, in another study conducted in prisons in the state of Mississippi in the USA, most chaplains who were involved in the religious programs understood that their function was primarily to support, encourage and share their faith with the inmates. Chaplains' efforts were to use their presence to transmit messages of hope to inmates at times when they were confronted with the negativity and the difficulties of the prison environment (11).

Volunteers in this study said that volunteering in prisons is important, and that it can bring benefits to the inmates and to themselves. This perception was previously described in another study conducted in the state of Florida in the USA, where it was found that volunteer visits can have a positive influence on the inmates, and influence their attitude while serving their sentence, contributing to the establishment of social relationships during incarceration (25, 26). A similar finding was reported in another study conducted in Hong Kong, emphasizing the importance of the role of volunteers during incarceration, where volunteers help inmates to build and improve their personal, family, and social relationships so that they can successfully re-enter in the society (10, 11).

Our study shows that some actions are required to improve the volunteering in the prison context in Portugal, namely: (i) providing training and access to support to volunteers who volunteer in prisons, so that volunteers know from the beginning what they can and cannot do, always complying with the necessary rules and avoiding any type of complication within the prison establishment that could jeopardize their safety, the safety of inmates and even the professional staff, (ii) improve the organization and the cooperation between the volunteering organizations and the prison establishment, providing more support from the prison establishment by improving conditions within the prison, so that volunteer activities can take place as naturally as possible and trying to achieve new areas of intervention within prisons, for example providing administrative support to technicians through monitoring, organizing processes and activities, (iii) improve the relationship that exists between society and the prison population as a way of contributing to reintegration and reducing the social stigma that these people face after serving their sentence and (iv) providing greater financial support to entities to be able to support the costs or facilitate more resources for the development of volunteering opportunities. According to the Portuguese legal framework of volunteering (Law No. 71/98, of November 3^rd), one of the rights of volunteers is the possibility of having voluntary social insurance (19). Therefore, in order to be able to support insurance, transport expenses and materials for activities, it is necessary that the entities have the required financial capacity (17).

Further research could investigate the perception of the inmates and the prison staff of volunteering in prisons, assess the proportion of people who volunteer in prisons and conduct follow-up studies to assess the long-term impact of volunteering in prisons for the inmates and for the volunteers themselves. Since the environment of different prisons may vary depending on their size or security level, future research should explore the differences in the provision of volunteering according to their level of security (low-security vs. high security) and prison size (small institutions with a few hundreds of inmates vs. larger jails with thousands of inmates).