It is widely recognised that children in care are over-represented in the criminal justice system and there have been calls for practice to change. In England and Wales, some local areas have set up protocols to detail how partner agencies will support children in care and prevent them from being drawn into the justice system. The protocols aim to reduce unnecessary police callouts to care placements and increase the use of diversionary and restorative approaches. Partner agencies seek to implement the protocols and question, “would this response be good enough for my child?”. In my PhD study, I am examining how children in care are supported by the presence of these protocols. The study employs a realist framework to explore how the protocols work, for whom, in what circumstances, and why. I am conducting interviews in several case study areas with managers and practitioners from the youth justice service, police, and care providers. The interviews will inform a programme theory that demonstrates how and why the protocols are anticipated to work to reduce the criminalisation of children in care.