The report first considers the case for and against protective penal measures -- the relationship of public opinion to actual risk, the hazards of modern societies, the efficacy of protective sentences, and the potential for modifying the environment to increase safety. Various methods of predicting dangerousness are critiqued for their high margin of error, which heightens the inherent injustice of protective confinement as currently practiced. The report presents an overview of the dangerous offender in England today, explaining court practices in life sentences, detention orders upon children and young persons, hospital restriction orders, extended sentences, determinate sentences, and ancillary orders. Detention practices are discussed in terms of security in prison, parole and release on license, and discharge from secure hospitals. The discretionary life sentence, used in cases where seriousnes of offense, offender dangerousness, and psychological disturbance are sentencing factors, lacks a clear legal rationale as a protective device against dangerous offenders. The task force proposes sentencing high-risk serious offenders within a statutory framework that would rationalize existing practices. It suggests that the legislature specify the concept of 'grave harm,' types of protective sentences, restrictions on eligibility for such sentences, procedural safeguards, appeal procedures, and provisions for release on license. Appendixes contain the consultative document, lists of respondents and institutions visited, and a discussion of methodological problems and empirical findings on determining dangerousness. An index and a bibliography of more than 200 references are provided.