Up to a quarter of a million vulnerable people are not being supported by an ‘appropriate adult’ while in police custody, a Home Office report suggests. It said lack of awareness and a shortage of trainees meant that police often ended up questioning adults with mental illness or learning disabilities without one. Appropriate adults are trained volunteers who help with communication during police interviews. They are supposed to ensure that mentally vulnerable people who are arrested or questioned understand what is happening, and that their legal rights and welfare are safeguarded. They were introduced in the 1980s following miscarriages of justice involving vulnerable people. Local authorities are required to provide appropriate adults whenever children are in contact with police and there is no parent or guardian present, but there is no duty to do the same in respect of vulnerable adults, many of whom only have the comprehension of a child.