Interrogation and Evidence Fabrication

I explore the rather common legally permissible practice of police lying to suspects and/or fabricating evidence by analyzing a simple model in which police can fabricate/lie and then the accused chooses whether to confess. When police are not permitted to fabricate/lie, the police presenting evidence, which in this case can be viewed as hard evidence, to the accused conveys information about the accused's chances at trial. However, when police are permitted to fabricate/lie, the evidence does not convey information to the accused. I find that allowing police to lie is helpful in cases where it either leads to a guilty accused confessing when he would otherwise go to trial, or an innocent accused not confessing when he otherwise would confess if police were not allowed to lie. However, allowing police to lie is harmful in cases where it either leads to a guilty accused not confessing when he would confess if the police were not allowed to lie, or an innocent accused confessing when he would not if police were not allowed to lie. These cases are characterized and some policy implications are provided.