Stop-and-identify laws have their roots in early English vagrancy laws under which suspected vagrants were subject to arrest unless they gave a "good account" of themselves; this practice, in turn, derived from the common-law power of any person to arrest suspicious persons and detain them until they gave "a good account" of themselves. Modern stop-and-identify laws combine aspects of the old vagrancy laws with a guide for police officers conducting investigatory stops, such as those authorized under "Terry v. Ohio", .