4 What is trust?

At every step of the crime scene to courtroom process, we need to consider whether those involved – victims, the accused, eyewitnesses and the jury – have trust in the justice system. Do they trust the police, the forensic science experts, digital evidence experts, legal practitioners and the legal processes represented by the court? Before we get to this, we should establish what trust is.

Trust in the CJS is shaped by people’s experiences and interactions with its institutions. It is based on the expectation that these institutions will fulfil their roles properly and fairly, in line with the overall purpose of the CJS (Bradford et al., 2008). There are many factors that can influence public trust in forensic science and the criminal justice in general. Research shows that trust is influenced by a mix of expertise and motives.

Trust is a foundational concept studied across many disciplines and may be defined as a psychological state considering the intention to be vulnerable based on positive expectations of another’s actions or intentions (Rousseau et al., 1998, p. 395). This definition bridges interpersonal (between individuals) and institutional (confidence in systems and structures) trust. Below are some explanations about how to define trust.

In psychology, trust is viewed as a cognitive and emotional process rooted in perceptions of others’ reliability and intentions. Trusting someone means we are willing to be vulnerable to someone as we have positive expectations of that person’s behaviour (Rotter, 1967; Mayer et al., 1995). Attachment theory shows that early relationships are crucial for developing trust, influencing how people navigate later relationships. Cognition research explores how past experiences and social cues inform judgements about trust. From neuroscience research we can see that trust activates the amygdala when we make decisions around trust. All of these frame trust as something that we learn and adapt to.

In sociology, trust is viewed as a social mechanism facilitating cooperation, increasing certainty, and enabling social order allowing society to function by simplifying choices and promoting stability (Luhmann, 1979).

Economists and political scientists view trust as a form of social capital. Social capital provides for individuals to develop social connections to build reciprocal trust with others. It also provides information about norms within society so that more trust in government is connected to greater compliance with criminal justice rules.

Studies in forensic science have found that people are more likely to trust experts who are not only knowledgeable and skilled but also show qualities like reliability, honesty, transparency and care for others. Trust also grows when experts are seen as independent and committed to acting in the public’s best interest (Hawkins, 2024; Hancock et al., 2023). The reliability and expertise of forensic scientists is aligned to communication of evidence and specifically the description of evidence through narrative (McCarthy, Wilcox & Nic Daeid, 2018).

A key factor in how the public views the justice system is whether people feel they are treated fairly. Sarat (1977) argues that unfair treatment is the main reason people lose trust in the police and the courts.