Research into the police's investigation in cases where there is a suspicion of domestic violence against children, has mostly examined what happens to the child during interrogation by specialists. By applying an interpretive understanding of the concept of competence, the present study examines the competence the police patrol needs with respect to taking care of the children's rights in such cases. Through in-depth interviews with 15 police officers, the analysis generates two main findings. First, an essential competence, in encounters with children, is to be able to strike a balance between human aspects and the requirements of the criminal law. This comprises an interpretive-relational attitude to securing the encounter in the 'window of opportunity'. Second, development of this competence is limited by contextual and organisational aspects. The article discusses the organisation's attempt to develop the officers' competence in such cases, and the challenges involved.