Tom is more likely to listen to the police officer. This is due to the police officer being a legitimate authority figure in comparison to the local adult. Research by Milgram suggests that obedience is due to perceiving legitimate authority. The police officer can cause sanctions for Tom's behaviour, such as a fine, whereas the local man cannot. Therefore, the police officer will be listened to because of the consequences perceived from the police officers authority.
In addition, the police officer wears a uniform. Research has shown that uniforms are powerful and influence social obedience. For example, Bickman (1974) shows that local people obeyed a security guard rather than a milkman. Therefore the police officer will have more of an impact on Tom because he wears a uniform, which influences the authority Tom perceives.