The term "in custody" has been debated in both "California v. Beheler" (in regards to what constitutes custody in the requirement to read Miranda rights) but also in other federal court cases related to Miranda law and definition of custody. Although Miranda law has roughly defined custody as the "formal arrest or restraint on freedom of movement," colloquial language may be less restrictive in the use of custody and is thus sometimes difficult to distinguish from the process of arrest. In addition to collecting data on those who have died in custody, the Bureau of Justice Statistics also tracks all deaths related to arrest. This aids in collecting data from the fringes of custody or attempts to arrest an individual.