While previous research has highlighted the positive consequences of a high trust in the police, parts of the French population exhibit a lack of trust toward the police. In this paper, I use a lab-in-the-field experiment in two high-schools in France to investigate the effect of a brief and controlled discussion – contact – between police officers and students on trust. Results indicate a positive effect of contact on trust at the individual level, i.e. toward the specific police officer met. The magnitude corresponds to an increase of approximately 0.4 standard deviation. However, the effect fails to translate to an increase in the police in general. A theoretical model of belief formation can shed light on why a single contact cannot be sufficient in case of prior – negative – interactions. This paper has implications for the most widely used policy to improve the perception of the police, namely community policing.