In the United States, LWOP was initially designed to eliminate the discretion of parole officials who have been criticized for being overly lenient in releasing life-sentenced inmates prior to serving an appropriate amount of time. In addition to its use as a punishment for habitual offenders, the other primary use of a LWOP sentence is as an alternative to the death penalty. Proponents of LWOP argue that this sentence ensures a severe punishment, but unlike capital punishment, allows redress for exonerating those wrongly convicted. Opponents of LWOP have challenged it on the grounds that the sentence is an affront to human rights and dignity because of its indeterminate nature. Specifically, its critics contend that it involves an undue level of suffering for long-term inmates who have no hope of release. Legally they contend such suffering constitutes cruel and unusual punishment. An examination of the international use of LWOP notes that although LWOP is not a sanction exclusive to the United States, it is used in the United States at a much higher frequency than other nations. This article also reviews U.S. Supreme Court cases relevant to the legal status of LWOP, and it presents an overview of public support for LWOP. A summary of the literature's findings on the "biopsychosocial" characteristics of LWOP inmates addresses their mental health and their institutional misconduct. The article concludes with a number of suggestions for future research on the LWOP sentence, including research on prosecutorial use of LWOP, a detailed profile on LWOP inmates, and an assessment of the cost-effectiveness of the sentence. 9 notes and 77 references