By analysing the 2016 Japanese Supreme Court case concerning family caregivers’ liability for damages caused by a person with dementia who was killed by a train while wandering, this article suggests how to address similar cases in the future, considering the rights of persons with dementia to live in the community. The Court absolved the deceased’s wife and son from liability and defined four criteria to find a person liable for damages: (a) the caregiver’s living, mental, and physical conditions; (b) the conditions of the caregiver’s involvement with a person with a mental disability; (c) the nature and incidence of the problematic behaviours of the person with a mental disability; and (d) the circumstances surrounding their supervision and care. This was the Supreme Court’s first presentation of the criteria for establishing liability for a ‘Person Equivalent to a Supervisor’. To guarantee the rights of a person with dementia to live in the community, the burden on family caregivers must be reduced, and the range of caregivers broadened to include non-family providers. The Court sought to reduce the caregivers’ burden, and if these criteria are applied appropriately, the human rights of dementia patients and caregivers will be protected.