Research investigating the link between mental health, crime and violence often rely on populations that are at a high-risk of violent and criminal behaviour, such as prison inmates and psychiatric patients. As a result of this selection bias, the relationship between mental health, criminal and violent behaviour is significantly over-estimated, with mental health being incorrectly linked with violent and criminal behaviours. This study examines the relationship between mental health, violence and crime in a more representative communitybased sample. One hundred and twenty-one individuals with and without a mental health disorder reported their involvement in crime and completed an aggression questionnaire. The results revealed that there is no statistically significant difference in terms of violence and crime involvement between individuals with a mental health diagnosis and those without.Moreover, the study did not find any statistically significant associations between specific mental health disorders and specific crime offences. The findings suggest that certain mental health disorders do not strongly contribute to crime violence and involvement. Limitations and implications are discussed in detail.

This study explores investigative decision-making processes in the context of major crimes as experienced by the law enforcement agents. Methodology: Episodic interviews were conducted with 6 agents from medium-sized police forces in the UK. Following the framework of Naturalistic inquiry, Qualitative Content Analysis took place with the assistance of Atlas.ti software. To ensure the validity of findings, the within method triangulation was preferred, by additionally analysing the interview transcripts with ALCESTE. Findings: Findings from this study revealed a variety of internal factors at play, shaping the decision making course into an act of balancing various desired goals. Detectives appear to assess a situation based on their experiences confirming that the Naturalistic Decision-making model may assist in understanding investigative decision-making. Limitations/implications: Due to the busy schedule of law enforcement agents the number of participants was limited and availability difficult; therefore, this study can be thought of as a pilot study that will inspire researchers to use the same method for in-depth understanding of investigative decision making. Practical implications: Results captured the ill-defined goals in the police environment and provided ways of decreasing their impact on investigative decision-making thus should help detectives to understand their decision-making limitations and strengths. Investigative Decision Making 2 Social implications: The findings from this project enhance the psychological understanding of investigative decision-making. Originality: This project assists in understanding the psychological aspect of investigative decision-making during police duty and provides the opportunity to law enforcement agents to revaluate situations in order to improve the investigative decision-making process; while adds to existing literature.