Criminal offenders who are very likely to commit serious crimes after serving their punishments constitute a great risk, a threat from which the general public expects to be protected. In a comparative legal study, we addressed the following issues based on an analysis of some 15 legal systems: What special liberty-infringing legal consequences can be imposed on what group of offenders under what circumstances and under what legal conditions?

Crim­in­al of­fend­ers who are very likely to en­gage in ser­i­ous crim­in­al activ­ity after serving their pun­ish­ments are con­sidered a se­cur­ity risk that must be countered by means of (ad­di­tion­al) liberty-in­fringing meas­ures. The pub­lic’s man­tra with re­spect to such of­fend­ers – es­pe­cially if they are sex of­fend­ers – is “lock them up forever”; the leg­al situ­ation in Ger­many is con­sidered un­sat­is­fact­ory, by some, des­pite sev­er­al re­forms since 1998. On the basis of some 15 (mostly European) leg­al sys­tems, this re­search pro­ject, which was be­gun in 2008, presents a com­par­at­ive over­view of what liberty-in­fringing leg­al con­sequences can be im­posed on what group of of­fend­ers un­der what cir­cum­stances and leg­al con­di­tions in or­der to serve so­ci­ety’s in­terest in pro­tec­tion from crim­in­al re­cid­iv­ists.

This tra­di­tion­al com­par­at­ive leg­al study con­sists of coun­try re­ports, pre­pared ac­cord­ing to a com­mon out­line, and a func­tion­al com­par­at­ive ana­lys­is. The func­tion­al ap­proach is use­ful in com­par­ing vari­ous se­cur­ity con­cepts. In some coun­tries, for ex­ample, stat­utory pun­ish­ment ranges and sen­ten­cing by the tri­al judge already re­flect the of­fend­er’s (typ­ic­al or in­di­vidu­al) de­gree of dan­ger­ous­ness. This is true even where life im­pris­on­ment is not a pos­sib­il­ity if very long pris­on sen­tences can be im­posed and/or if in the case of mul­tiple of­fenses the length of the – cu­mu­lat­ive – sen­tence im­posed is not lim­ited by the bio­lo­gic­al life ex­pect­ancy of the con­victed of­fend­er. Like­wise, the re­peated com­mis­sion of ser­i­ous crimes can be countered by means of stat­utory pen­alty en­hance­ments, be it be­cause these en­hance­ments have a de­terrent ef­fect on some po­ten­tial of­fend­ers or be it be­cause re­peat of­fend­ers who are not de­terred are sen­tenced to longer pris­on terms than are first of­fend­ers. In the met­ing out pun­ish­ment, it is pos­sible that a dis­tinc­tion is already made between com­pon­ents of the sen­tence that re­flect culp­ab­il­ity and those that re­flect dan­ger­ous­ness. Fi­nally, the pro­ject ana­lyzed the ex­tent to which un­fa­vor­able crim­in­al pro­gnoses are con­sidered in de­cisions about con­di­tion­al early re­lease from cus­tody.

For those leg­al sys­tems that provide spe­cial, liberty-in­fringing se­cur­ity meas­ures in ad­di­tion to the de facto pun­ish­ment of crim­in­ally re­spons­ible of­fend­ers, we com­pared the sub­stant­ive re­quire­ments of these meas­ures as well as their ba­sic pro­ced­ur­al para­met­ers. Be­sides pos­sible pri­or and pre­dic­ate of­fenses and the crim­in­al sanc­tions im­posed for these of­fenses, we paid spe­cial at­ten­tion to the cri­terion of the dan­ger­ous­ness of the of­fend­er, i.e., the like­li­hood that he or she will re­offend. In this con­text, we also ana­lyzed pos­sible dif­fer­ences between the pre­requis­ites for im­pos­ing se­cur­ity meas­ures on sex of­fend­ers and those for im­pos­ing se­cur­ity meas­ures on oth­er de­lin­quents. An­oth­er per­son­al of­fend­er char­ac­ter­ist­ic that may be sig­ni­fic­ant is a pos­sible min­im­um-age re­quire­ment at the time of crime com­mis­sion or at the time of sen­ten­cing. As far as pro­ced­ure is con­cerned, in ad­di­tion to the point in time at which a de­cision is made re­gard­ing the im­pos­i­tion of a liberty-in­fringing se­cur­ity meas­ure (already at the time of sen­ten­cing or not un­til after the sen­tence has been served), the tech­niques em­ployed to fore­cast the de­gree of dan­ger­ous­ness are also of great rel­ev­ance. Of no less sig­ni­fic­ance are the stat­utory pro­ced­ures ac­cord­ing to which the need to con­tin­ue or the pos­sib­il­ity of ter­min­at­ing a se­cur­ity meas­ure are eval­u­ated. As a con­sid­er­able peri­od of time may pass between the com­mis­sion of a pre­dic­ate of­fense, sen­ten­cing, and the end of the serving of the sen­tence and/or the liberty-in­fringing se­cur­ity meas­ure, we also stud­ied the ex­tent to which any changes in le­gis­la­tion that have taken place dur­ing this time should be con­sidered in sub­sequent judg­ments on the im­pos­i­tion, con­tinu­ation, or ter­min­a­tion of a liberty-in­fringing se­cur­ity meas­ure.