Life imprisonment in Germany
In Germany, a prisoner sentenced to life imprisonment (lebenslange Freiheitsstrafe) normally may apply for parole after having served 15 years. If the parole court rejects the application, the inmate may reapply after a court determined blocking period no longer than two years (§ 57a IV StGB). If the court has determined a "severe gravity of guilt" exists (besondere Schwere der Schuld), parole is delayed for a non-specific period beyond 15 years (§ 57a StGB).
In declining a prisoner's first application for parole, the parole court determines a lack of suitability based on the extreme gravity of the offence, as well as the development (or lack thereof) of the prisoner behind bars. Such determination includes how many additional years the inmate must serve before again being eligible to apply for early release. There is no legal limit on the term the parole court can hand down, though in practice the average term is about 5 years, and longer periods are rare.
In the case of one Red Army Faction terrorist, the parole court ordered a deferment of at least 11 years (making his sentence a minimum of 26 years) before he again became eligible for parole. Such a long length was due to his involvement in multiple killings, lack of remorse, and his affiliation with a terrorist group.
In another case, a court ruled the defendant had to serve at least 38 years in prison for the killings of five people. He was incarcerated beyond the required 38 years after it was determined he was a danger to society. Such a ruling mandates continued imprisonment de jure, as being safe toward society is required to be paroled from a life sentence (§ 57a I Nr. 3 StGB in conjunction with § 57 I Nr. 2 StGB). However, the case was appealed to the German Constitutional Court (BVerfG, Judgment from 29.11.2011 - 2 BvR 1758/10), which held that the decision to hold the prisoner beyond the original 38 years was unconstitutional for case-specific reasons.
In instances where the convict is found to pose a clear and present danger to society, the sentence may include a provision for preventive detention (German: Sicherungsverwahrung) after the actual sentence is satisfied. This is technically not considered a punishment, but a decision to protect the public, and elements of prison discipline that are not directly security-related are relaxed for those in preventive detention. The preventive detention may be continued every two years until it is found the convict is unlikely to commit further crimes or be a menace to the public. Since 2004, it has also been possible for preventive detention to be ordered by a court after the original sentencing if the danger that a criminal poses upon release becomes obvious during their imprisonment. Despite its non-punitive status and the broadness of its potential application, though, preventive detention is used only in exceptional cases.
Paroled prisoners usually must stay in regular contact with a civilian "parole helper" (Bewährungshelfer) for the duration of their parole. The parole period in the case of life imprisonment is five years (§ 57 III StGB).
The German Constitutional Court has found life imprisonment without the possibility of parole to be antithetical to human dignity. The ruling does not mean that every convict has to be released, but that every convict must have a realistic chance for eventual release, provided they are considered safe to the community.
As a formality, the inmate has to agree to his release on parole (§ 57a I Nr. 3 StGB). Displays of contrition or appeals for mercy are not a condition for such a release.
One of the most prominent "long termer" has been Heinrich Pommerenke, who in total had served 49 years, from 1959 until his death in 2008, for mass murderer and rape. Currently (May 2014), the record is held by Hans-Georg Neumann who was sentenced to life in prison in 1963 for murdering a pair of lovers and completed 52 years (including pretrial detention) in prison in 2014. 
According to data from the federal ministry of justice (1998) the average time served for a life sentence in Germany is 19.9 years.
Life Imprisonment: mandatory sentence for
Possible sentence for
Planning a war of aggression, high treason, treason, illegal disclosure of secrets, engaging in relations that endanger peace, child abuse causing death, sexual assault causing death, robbery causing death, arson causing death, abduction for the purpose of blackmailing causing death, taking hostages causing death, effecting a nuclear explosion causing death, effecting an explosion causing death, misuse of ionizing radiation causing death, attacking a driver for the purpose of committing a robbery causing death, and attacking air or sea traffic causing death. Most life sentences are given for murder.
- http://www.focus.de/politik/deutschland/raf/ex-raf-terrorist-christian-klar-kommt-nach-26-jahren-frei_aid_350794.html (in German; Article about former Red Faction Terrorist Christian Klar leaving prison after 26 years in jail)
- http://dejure.org/dienste/vernetzung/rechtsprechung?Gericht=OLG%20N%FCrnberg&Datum=02.08.2010&Aktenzeichen=2%20Ws%20172/10 (text in German)
- http://www.hrr-strafrecht.de/hrr/bverfg/10/2-bvr-1758-10.php (text in German)
- Judgement of June 21st 1977, BVerfGE 45, 187 (in German)
- article from 2008-12-19 in "Stuttgarter Nachrichten"
- article from 2008-12-30 in "Stuttgarter Nachrichten"
- Online news article in N24 (Text in German)
- § 211 German federal punishment code
- § 6, 7 and 8 German federal code of crimes against international law
- German criminal code