People v. Beardsley 150 Mich. 206, 113 N.W. 1128 (1907) is a well-known case that illustrates the parameters around the legal necessity of a duty to act, and the criminal liability of failure to act when there is an obligation to provide reasonable assistance. In Jones v. United States 308 F.2d 307 (D.C. Cir. 1962), the categories falling under this legal duty were set forth. They include duties based on statute, duties based on contract, duties based on the voluntary assuming of responsibility as for the care of a child, and duties based on legal relationships, such as between parent and child or husband and a wife.
