Pinnick (plaintiff) alleged he was in an automobile accident in Massachusetts caused solely by the negligence of Cleary (defendant). Pinnick brought suit against Cleary seeking both actual damages and pain and suffering damages. A Massachusetts no-fault statute was in effect which provided limited damages for minor injuries regardless of fault, but limited recovery for pain and suffering if a plaintiff’s medical expenses did not exceed $500, subject to certain exceptions. Pinnick received initial damages under the statute, but his medical expenses did not exceed $500 and he did not fall into one of the categorical exceptions for receiving pain and suffering damages. Pinnick was denied recovery and appealed on the ground that the statute deprived him of a “vested property right” amounting to the right to seek full recovery in tort, and violated his due process rights protection by the Bill of Rights in the Constitution.