Secondary Logo

Journal Logo


Preservation of Forensic Evidence by Nurses in a Prehospital Emergency Care Service in Brazil

Silva, Juliana O. M. MPH; Santos, Luiz F. S. RN; dos Santos, Suelen M. RN; da Silva, Denison P. PhD; Santos, Victor S. PhD; de Melo, Claudia M. PhD

Author Information
doi: 10.1097/JTN.0000000000000483
  • Free


Violence promotes negative changes in the epidemiological profile of a population and harms both individuals and society as a whole. There are many forms of violence, and it is seen as a major public health problem (Garcia & Silva, 2018). Violence can be promoted by factors that favor its emergence and maintenance, such as cultural differences, globalization, interpersonal relations, socioeconomic factors, and environmental changes, among others. It directly affects individuals emotionally, physically, and economically, and it also has great financial costs. Violence is not just restricted to urban areas, it also occurs in rural areas (Vieira, 2016).

Nurses working in prehospital and emergency settings are on the front line of providing health care to those affected by violence. This care not only includes physical and emotional support but also includes forensic skills such as the responsibility to preserve, collect, document, and store evidence left by the perpetrator that may impact the investigation (Ministério da Saúde, Departamento de Vigilância de Doenças e Agravos não Transmissíveis e Promoção da Saúde, 2013). Prehospital care nurses are often the first to arrive even before the police and other services. The preservation of the place where the victim was found, as a crime scene, is the first step to guarantee the integrity of important evidence (Silva, 2010). Crime scenes often contain biological and nonbiological artifacts of physical evidence such as hairs, fibers, glass, blood, and skin. The evidence is fundamental to criminal investigations and must be preserved (Silva, 2010). The record of the collection, control, transfer, and analysis of forensic evidence is known as the chain of custody and must be rigorously followed because any failure during this process can lead to the failure of the investigation. However, few nurses historically have received training in evidence collection as part of a standard nursing curriculum or continuing education program (Kent-Wilkinson, 2011). This study aimed to correlate nurses' knowledge with the execution of procedures related to forensic evidence collection.


This was a descriptive survey study of nurses working in the prehospital Mobile Emergency Care Service (SAMU) in Aracaju, Sergipe, a poor region with high rates of violence in Northeast Brazil. The SAMU is a free, 24-hr prehospital service comprising a team of physicians, nurses, nursing assistants, and lifesaving trained drivers. The study population consisted of 128 nurses from the Advanced Support Units of SAMU. The data collection period was from September 2017 to February 2018. The study involved completing a questionnaire, with 32 questions related to forensic evidence procedures as well as demographic information of the participants. A total of 140 questionnaires were distributed and 128 (91.4%) were completed. All questionnaires were self-completed, anonymously, in a quiet private place. The questionnaire assessed nurses' knowledge and execution of procedures related to forensic evidence documentation, collection, and preservation using three-point Likert scale answer options. Knowledge was assessed by the following responses: “I did not know,” “I knew a little, or “I knew a lot.” Execution of procedures was assessed by the following responses: “I have done it,” “I have not done it,” and “not applicable.”

Rates of both knowledge and execution, specific and overall, were calculated using the following formulas:

  • Knowledge rate in documenting = (Number of actions the individual knows/36) × 100
  • Execution rate on documenting = (Number of actions the individual performs/36) × 100
  • Preservation knowledge rate = (Number of actions the individual knows/31) × 100
  • Execution rate in preserve = (Number of actions that individual performs/31) × 100
  • Collect knowledge rate = (Number of actions the individual knows/32) × 100
  • Execution rate on collect = (Number of actions that individual performs/32) × 100
  • Total knowledge rate = (Number of actions the individual knows/99) × 100
  • Total execution rate = (Number of actions that individual performs/99) × 100

Specific questions on the preservation of evidence at the crime scene during prehospital care were calculated from the following equations:

  • Knowledge rate of individuals in relation to specific questions = (Number of actions that individual knows of specific questions/18) × 100
  • Execution rate of individuals in relation to specific questions = (Number of actions that individual performs on specific question/18) × 100

After categorizing the knowledge rates in three groups (<50%, between 50% and 70%, and <70%), absolute (n) and relative (%) frequencies were obtained. Frequencies were used to assess the occurrence of visits to victims, the type of violence visualized, the evidence considered as indicative of crime, whether the nurses considered it important to preserve evidence, whether they felt that the preservation of forensic evidence is attributed to health professionals, whether they considered themselves prepared to perform such activity, and whether there is was a protocol for this service. Mean and standard deviation were used for numerical variables (age, time from graduation, and working time in the emergency/urgency).

For analysis of the rates as numerical variables, it was necessary to verify the distribution of the normality of the scores using the Shapiro–Wilk test. When the asymmetry of variables (nonparametric) was identified, Kendall's Tau-b test was used to evaluate the correlation of scores between knowledge and performance. Linear regression was used to assess the total knowledge rate with the total execution rate. The Statistical Package for the Social Sciences, Version 22.0 (IBM SPSS software) was used for the statistical analysis, and the adopted confidence interval was 95% (p < .05).

The study was approved by the ethics committee in research with human beings of Tiradentes University (Protocol No. 2.135.510). All included participants gave their written consent to participate. The study followed the ethical precepts contained in the CONEP Brazil resolution and observed the Helsinki statement.


A total of 128 nurses completed the survey. Table 1 shows that the majority of the sample was female (82.8%), with a mean age of 37.2 years. The mean number of years employed in practice was 11.4 and that in emergency services was 7.6. Nurses reported the frequency of time spent providing care for victims of violence as 41.4% daily, 29.7% three times a week, and 25.0% at least once a week. Table 2 shows that the two most common injuries were firearm related (31.4%), followed by stab or penetrating wounds (27.4%). The presence of blood (12.9%) and knives (10.2%) were the most commonly reported vestiges of evidence.

Sociodemographic Characteristics of Study Participants
Source of Injuries and Forensic Evidence That the Study Participants Reported

In respect of the difficulties encountered by the nurses in the collection and preservation of forensic evidence, the most important were the demands of the emergency services (41.9%), lack of knowledge about the procedures for collecting and storing materials (64.5%), not being able to identify what is evidence (74.2%), and overwork (9.7%).

Regarding the preservation of forensic evidence, 95% of the nurses stated that it was important to preserve evidence at the scene; 65.2% agreed that this is part of their job, although most of them reported that they did not feel prepared to preserve the evidence found (95%). In total, 80.5% of the nurses responded that the health institutions that received the victims of violence do not have protocols for the identification, collection, and preservation of forensic evidence.

Table 3 shows a breakdown of the results regarding knowledge and execution by the nurses regarding actions related to the documentation, preservation, and collection of forensic evidence in prehospital care. In total, 57.9% of nurses reported that they performed more than 50% of the documentation procedures, whereas only 0.8% reported performing the procedures related to the preservation of evidence and 5.5% related to data collection. More than 50% of nurses reported knowing most of the items for documentation, but only 10.2% knew the procedures for preservation and collection of evidence. Table 4 shows that the majority of the nurses knew (93.8%) and performed less than 50% of the procedures necessary (89.8%) to preserve evidence at the crime scene.

Execution and Knowledge of Nurses About the Procedures for the Preservation and Collection of Forensic Evidencea
Nurses Knowledge and Execution of Procedures for Preserving Forensic Evidence From Scenes of Violencea

Table 5 reveals the correlation of forensics knowledge to forensic procedure execution by the nurses. There was a strong correlation between knowledge and documentation (r = .71) and a weak correlation between knowledge and collection (r = .47) and between knowledge and preservation of evidence (r = .47), with statistical significance (p < .001). There was an overall linear relationship between knowledge and all listed procedures, with statistical significance (p < .05) with a Pearson's correlation (r = .69)

Relationship Between Knowledge and Execution of the Forensic Evidence Procedures Among Nurses From Prehospital Care in Aracaju, Brazil


This study investigated the relationship of knowledge and the execution of procedures related to the preservation of forensic evidence by nurses in the prehospital health service in a poor region with high rates of violence in Northeast Brazil. Although there was an overall linear relationship between knowledge and all listed procedures, correlation strength varied across individual procedures. A higher correlation exists between knowledge and documentation than with knowledge and collecting and preserving evidence.

Others have reported similar results. In a study conducted in Saudi Arabia with 96 nurses working in emergency services, a deficiency in skills and knowledge about forensic procedures was observed, with more than 85% of the nurses reported not having undergone evidence preservation training, although most reported that there were well-established protocols in their institution (Alsaif, Alfaraidy, Alsowayigh, Alhusain, & Almadani, 2014). A study conducted in Turkey showed that more than 80% of professionals recognized the types of evidence, although they lacked sufficient knowledge for its collection and storage, and that one in four subjects did not protect/store the remains, nor did they refer them to the appropriate authorities (Asci, Hazar, & Sercan, 2015). It is noteworthy that in our study, nurses preserved more forensic evidence in firearm-related injuries compared with other workers. Our findings are also consistent with the study conducted by Silva (2010) on 204 nurses in emergency services in Portugal. This study demonstrated that professionals recognized the importance of documentation in criminal investigations and the legal process, with regard to recording the clinical process (65.77%) and the statements made by the victims (93.24%), as well as the documentation of any marks present on the bodies of the victims (96.62%).

Our study results are likely influenced by the lack of forensic evidence education provided during nurses academic training, the absence of institutional protocols, and the absence of continuous in-service training. Peel (2016) similarly reported that nurses require baseline forensic evidence knowledge and continuous training to improve their performance in the emergency department. Others have identified the following: lack of knowledge about the subject, the type of care provided to the victim, lack of time, the absence of a protocol guiding scene care, as well as fear of legal responsibility or reprisal as factors affecting nurse performance of forensic evidence processing (Cordoma, 2016; Filmalter, Heyns, & Ferreira, 2018; Henderson, Harada, & Amar, 2012; I·lçe, Yildiz, Baysal, Özdoğan, & Taş, 2010; Karadayi, Kolusayin, Kaya, & Karadayi, 2013).


This study reveals the need for the development of institutional protocols to guide nursing forensic evidence practice. In the state of Sao Paulo, a prehospital care protocol was established for cases of violence for use by the SAMU. During the care of the patient, the professional should accurately describe the position in which the victim was found and if it was necessary to move the victim, record the names and other services present at the scene, including vehicle registration numbers. It is recommended to only move the patient for evaluation or procedures, and if found dead, the body should not be put back in its initial position if it has been moved, but this should be reported to the police. Also, it is necessary to accurately describe the injuries, including any caused by the team in the process of care. In relation to the scene, team professionals should inform the police of the movement of any item, forward all medical and hospital materials used such as gloves, gauzes, and other waste for referral to the police forensic service, and document all the care provided including the name of the officer to whom the objects were sent (Secretaria Municipal da Saúde de São Paulo, 2014).

From the moment of patient contact, all data regarding the history of the violence, the injury mechanism, and the assistance provided must be documented chronologically because they may be used as a source of medical-legal information during the judicial process. This includes the use of diagrams to remember the marks on the body regions, including their size, shape, color, and location (Braz, 2010; Darnell, 2011).


This study's findings must be viewed within the consideration of its limitations. The study information is collected from self-reported data and is devoid of direct observation, making it difficult to confirm actual care provided. This means that the actual results may be lower than those reported in the study. Generalizability is limited because of a small sample size of data collected from only one region. Finally, a descriptive survey design does not determine a causal relationship between knowledge and execution of procedures. Despite these limitations, this study reveals an important gap between nurses' knowledge and the execution of procedures related to forensic evidence collection in Brazil.


Although nurses agree that forensic evidence should be documented, collected, and preserved, they often do not perform the actual forensic evidence procedures. To address this gap, forensic evidence principles should be incorporated into nursing curricula at all levels and provided as continuing education in an ongoing basis. Evidence-based institutional protocols are required to improve practice, especially among nurses with high workloads in fast-paced environments. Future studies should report observational data on nursing adherence to established institutional protocols and examine the perceived barriers between knowledge and action.


Alsaif D. M., Alfaraidy M., Alsowayigh K., Alhusain A., Almadani O. M. (2014). Forensic experience of Saudi nurses; An emerging need for forensic qualification. Journal of Forensic and Legal Medicine, 27, 13–16. doi:10.1016/j.jflm.2014.07.004
Asci O., Hazar G., Sercan I. (2015). The approach of prehospital health care personnel working at emergency stations towards forensic cases. Turkish Journal of Emergency Medicine, 15(3), 131–135. doi:10.1016/j.tjem.2015.11.007
Braz J. (2010). Investigação Criminal: a Organização, o Método e a prova: os desafios da nova criminalidade [Criminal investigation: The organization, the method and the proof: The challenges of new crime]. Coimbra, Portugal: Almedina SA.
Cordoma J. V. (2016). Exploring and understanding the factors that may influence the outlook of registered nurses regarding potential criminal evidence identification, collection and preservation on patients presented to them. Available from Seton Hall University Dissertations and Theses (ETDs). (Accession No. 2146). Retrieved from
Darnell C. (2011). Forensic science in healthcare: Caring for patients, preserving the evidence (p. 373). Boca Raton, FL: CRC Press.
Filmalter C. J., Heyns T., Ferreira R. (2018). Forensic patients in the emergency department: Who are they and how should we care for them? International Emergency Nursing, 40, 33–36. doi:10.1016/j.ienj.2017.09.007
Garcia L. P., Silva G. D. M. (2018). Violência por parceiro íntimo: perfil dos atendimentos em serviços de urgência e emergência nas capitais dos estados brasileiros, 2014 [Intimate partner violence: Profile of attending in urgency and emergency care services in Brazilian state capitals, 2014]. Cadernos de Saúde Pública, 34(4), e0006231. doi:10.1590/0102-311X00062317
Henderson E., Harada N., Amar A. (2012). Caring for the forensic population: Recognizing the educational needs of emergency department nurses and physicians. Journal of Forensic Nursing, 8(4), 170–177. doi:10.1111/j.1939-3938.2012.01144
Ilçe A., Yildiz D., Baysal G., Özdoğan F., Taş F. (2010). Analysis of the knowledge and practices of health care workers in emergency departments regarding the protection and preservation of evidence in forensic cases. Ulusal Travma ve Acil Cerrahi Dergisi, 16, 546–551.
Karadayi B., Kolusayin M. O., Kaya A., Karadayi S. (2013). Collection and transfer of biological materials from forensic cases in emergency units. Marmara Medical Journal, 26, 111–117. doi:10.5472/MMJ.2013028910
Kent-Wilkinson A. (2011). Forensic nursing educational development: An integrated review of the literature. Journal of Psychiatric and Mental Health Nursing, 18, 236–246.
Ministério da Saúde. Conselho Nacional de Saúde. (2012). Resolução 466 de 12 de dezembro de 2012 [Resolution 466 of December 12, 2019]. Retrieved from
    Ministério da Saúde, Departamento de Vigilância de Doenças e Agravos não Transmissíveis e Promoção da Saúde. (2013). Sistema de Vigilância de Violências e Acidentes: 2009, 2010 e 2011 [System of violence and accidents: 2009, 2010 e 2011]. Retrieved from
    Peel M. (2016). Opportunities to preserve forensic evidence in emergency departments. Emergency Nurse, 24(7), 20–26. doi:10.7748/en.2016.e1618
    Secretaria Municipal da Saúde de São Paulo. (2014). Protocolos de atendimento pré-hospitalar: suporte avançado à vida [Emergency care protocols: advanced life support]. Retrieved from
    Silva C. J. C. (2010). Os Enfermeiros e a preservação de vestígios perante vítimas de agressão sexual, no serviço de urgência [The nurses and the preservation of vestiges from victims of sexual aggression, in the emergency service] (Dissertação Mestrado Integrado em Medicina). Universidade do Porto, Porto, Portugal. Retrieved from
    Vieira P. M. S. (2016). Abuso sexual—Protocolos hospitalares no serviço de urgência [Sexual abuse—Hospital protocols in the emergency service] (Dissertação Mestrado Integrado em Medicina). Universidade de Porto, Porto, Portugal. Retrieved from

    Crime scene; Forensic evidence; Nurses

    Copyright © 2020 by the Society of Trauma Nurses.