Life imprisonment is any sentence of imprisonment for a crime under which convicted people are to remain in prison either for the rest of their natural lives or until pardoned, paroled or otherwise commuted to a fixed term. Crimes for which, in some countries, a person could receive this sentence include murder, attempted murder, conspiracy to commit murder, apostasy, terrorism, severe child abuse, rape, child rape, espionage, treason, high treason, drug dealing, drug trafficking, drug possession, human trafficking, severe cases of fraud, severe cases of financial crimes, aggravated criminal damage in English law, and aggravated cases of arson, kidnapping, burglary, or robbery which result in death or grievous bodily harm, piracy, aircraft hijacking, and in certain cases genocide, ethnic cleansing, crimes against humanity, certain war crimes or any three felonies in case of three-strikes law. Life imprisonment (as a maximum term) can also be imposed, in certain countries, for traffic offenses causing death. Life imprisonment is not used in all countries; Portugal was the first country to abolish life imprisonment, in 1884.
Where life imprisonment is a possible sentence, there may also exist formal mechanisms for requesting parole after a certain period of prison time. This means that a convict could be entitled to spend the rest of the sentence (until that individual dies) outside prison. Early release is usually conditional on past and future conduct, possibly with certain restrictions or obligations. In contrast, when a fixed term of imprisonment has ended, the convict is free. The length of time served and the conditions surrounding parole vary. Being eligible for parole does not necessarily ensure that parole will be granted. In some countries, including Sweden, parole does not exist but a life sentence may – after a successful application – be commuted to a fixed-term sentence, after which the offender is released as if the sentence served was that originally imposed.
In many countries around the world, particularly in the Commonwealth, courts have the authority to pass prison terms that may amount to de facto life imprisonment. For example, courts in South Africa have handed out at least two sentences that have exceeded a century, while in Tasmania, Australia, Martin Bryant, the perpetrator of the Port Arthur massacre in 1996, received 35 life sentences plus 1,652 years without parole, and James Holmes, perpetrator of the 2012 Aurora, Colorado shooting, received 12 consecutive life sentences plus 3,318 years without the possibility of parole.  Sentence without parole effectively means a sentence cannot be suspended; the prisoner may, however, effectively be released following a pardon, either on appeal, retrial or humanitarian grounds, such as imminent death. In several countries where "de facto" life terms are used, this is commonplace, such as in the case of Abdelbaset al-Megrahi.
A few countries allow for a minor to be given a lifetime sentence with no provision for eventual release; these include Antigua and Barbuda, Argentina (only over the age of 16), Australia, Belize, Brunei, Cuba, Dominica, Saint Vincent and the Grenadines, the Solomon Islands, Sri Lanka, and the United States. According to a University of San Francisco School of Law study, only the U.S. had minors serving such sentences in 2008. In 2009, Human Rights Watch estimated that there were 2,589 youth offenders serving life sentences without the possibility for parole in the U.S. The United States leads in life sentences (both adults and minors), at a rate of 50 people per 100,000 (1 out of 2,000) residents imprisoned for life.
In 2011, the Supreme Court of the United States ruled that sentencing minors to life without parole, automatically (as the result of a statute) or as the result of a judicial decision, for crimes other than intentional homicide, violated the Eighth Amendment's ban on "cruel and unusual punishments", in the case of Graham v. Florida.
Graham v. Florida was a significant case in juvenile justice. In Jacksonville, Florida, Terrence J. Graham tried to rob a restaurant along with three adolescent accomplices. During the robbery, one of Graham's accomplices had a metal bar that he used to hit the restaurant manager twice in the head. Once arrested, Graham was charged with attempted armed robbery and armed burglary with assault/battery. The maximum sentence he faced from these charges was life without the possibility of parole, and the prosecutor wanted to charge him as an adult. During the trial, Graham pleaded guilty to the charges, resulting in three years of probation, one year of which had to be served in jail. Since he had been awaiting trial in jail, he already served six months and therefore was released after six additional months.
Within six months of his release, Graham was involved in another robbery. Since he violated the conditions of his probation, his probation officer reported to the trial court about his probation violations a few weeks before Graham turned 18 years old. It was a different judge presiding over his trial for the probation violations a year later. While Graham denied any involvement of the robbery, he did admit to fleeing from the police. The trial court found that Graham violated his probation by "committing a home invasion robbery, possessing a firearm, and associating with persons engaged in criminal activity", and sentenced him to 15 years for the attempted armed robbery plus life imprisonment for the armed burglary. The life sentence Graham received meant he had a life sentence without the possibility of parole, "because Florida abolished their parole system in 2003".
Graham's case was presented to the United States Supreme Court, with the question of whether juveniles should receive life without the possibility of parole in non-homicide cases. The Justices eventually ruled that such a sentence violated the juvenile's 8th Amendment rights, protecting them from punishments that are disproportionate to the crime committed, resulting in the abolition of life sentences without the possibility of parole in non-homicide cases for juveniles.
In 2012 the Supreme Court ruled in the case of Miller v. Alabama in a 5–4 decision and with the majority opinion written by Associate Justice Elena Kagan that mandatory sentences of life in prison without parole for juvenile offenders are unconstitutional. The majority opinion stated that barring a judge from considering mitigating factors and other information, such as age, maturity, and family and home environment violated the Eighth Amendment ban on cruel and unusual punishment. Sentences of life in prison without parole can still be given to juveniles for aggravated first-degree murder, as long as the judge considers the circumstances of the case.
In a number of countries, life imprisonment has been effectively abolished. Many of the countries whose governments have abolished both life imprisonment and indefinite imprisonment have been culturally influenced or colonized by Spain or Portugal and have written such prohibitions into their current constitutional laws (including Portugal itself but not Spain).
A number of European countries have abolished all forms of indefinite imprisonment, including Croatia and Spain, which set the maximum sentence at 40 years (for each conviction, which in practice keeps the possibility of de facto life imprisonment), Bosnia and Herzegovina, which sets the maximum sentence at 45 years, and Portugal, which abolished all forms of life imprisonment with the prison reforms of Sampaio e Melo in 1884 and sets the maximum sentence at 25 years.
Norway (de jure) and Spain (de facto from 1993 until February 2018, the question is now debated of reintroducing de jure life imprisonment, its habitual practice before it became a democracy in 1978–1983) have abolished life imprisonment but retain other forms of indefinite imprisonment.
In Europe, there are many countries where the law expressly provides for life sentences without the possibility of parole. These countries are England and Wales (within the United Kingdom), the Netherlands, Moldova, Bulgaria, Italy, Hungary, Austria, Malta, Cyprus, Albania, Ukraine and the Republic of Ireland.
In Sweden, although the law does not expressly provide for life without the possibility of release, some convicted persons may never be released, on the grounds that they are too dangerous. In Italy, persons that refuse to cooperate with authorities and are sentenced for mafia activities or terrorism are ineligible for parole and thus will spend the rest of their lives in prison. In Austria, life imprisonment will mean imprisonment for the remainder of the offender's life if clemency is rejected by the President of Austria, and in Malta, there is never any possibility of parole for any person sentenced to life imprisonment, and any form of release from a life sentence is only possible by clemency granted by the President of Malta.[needs update] In France, while the law does not expressly provide for life imprisonment without any possibility of parole, a court can rule in exceptionally serious circumstances that convicts are ineligible for parole if convicted of child murder involving rape or torture, premeditated murder of a state official or terrorism resulting in death. In Moldova, there is never a possibility of parole for anyone sentenced to life imprisonment, as life imprisonment is defined as "deprivation of liberty of the convict for the entire rest of his/her life". Where mercy is granted in relation to a person serving life imprisonment, imprisonment thereof must not be less than 30 years. In Ukraine, life imprisonment means for the rest of one's life with the only possibilities for release being a terminal illness or a Presidential pardon. In Albania, no person sentenced to life imprisonment is eligible for parole; this effectively means imprisonment for the natural life of the convicted person, unless the prisoner is found not likely to re-offend and has displayed good behavior, and the convicted person has served at least 25 years.
In the Netherlands, there is never a possibility of parole for any person sentenced to life imprisonment, and any form of release for life convicted in the country is only possible when granted royal decree by the King of the Netherlands, with the last granting of a pardon taking place in 1986 when a terminally ill convict was released. As of 1970, the Dutch monarch has pardoned a total of three convicts. Although there is no possibility of parole eligibility, since 2016 prisoners sentenced to life imprisonment in the Netherlands are eligible to have their cases reviewed after serving at least 25 years.
Even in other European countries that do provide for life without parole, courts continue to retain judicial discretion to decide whether a sentence of life should include parole or not. In Albania, the decision of whether or not a life convicted person is eligible for parole is up to the prison complex after 25 years has been served, and release eligibility depends on the prospect of rehabilitation and how likely he or she is to re-offend. In Europe, only the Netherlands, Ukraine, Moldova and Malta explicitly preclude parole or any form of release for life sentences in all cases.
In South and Central America, Honduras, Nicaragua, El Salvador, Costa Rica, Venezuela, Colombia, Uruguay, Bolivia, Ecuador, and the Dominican Republic have all abolished life imprisonment. The maximum sentence is 75 years in El Salvador, 60 years in Colombia, 50 years in Costa Rica and Panama, 40 years in Honduras, 30 years in Nicaragua, Bolivia, Uruguay, and Venezuela, and 25 years in Paraguay and Ecuador. Brazil has a maximum sentence of 40 years under the Penal Code, but life imprisonment and capital punishment are provided by law for military crimes committed during wartime (such as treason, desertion, and mutiny) in the Constitution.
For Canada, the minimum is 25 years with parole eligibility increasing between second (murder that is not first degree murder is second degree murder) and first degree murder. In the United States, a 2009 report by the Sentencing Project suggested that life imprisonment without parole should be abolished in the country. U.S. law enforcement officials opposed its proposed abolition.
Pope Francis called for the abolition of both capital punishment and life imprisonment in a meeting with representatives of the International Association of Penal Law. He also stated that life imprisonment, removed from the Vatican City penal code in 2013, is just a variation of the death penalty.
In Singapore, before 20 August 1997, the law decreed that life imprisonment is a fixed sentence of 20 years with the possibility of one-third reduction of the sentence (13 years and 4 months) for good behaviour. It was an appeal by Abdul Nasir bin Amer Hamsah on 20 August 1997 that led to the law in Singapore to change the definition of life imprisonment into a sentence that lasts the remainder of the prisoner's natural life, with the possibility of parole after at least 20 years. Abdul Nasir was a convicted robber and kidnapper who was, in two separate High Court trials, sentenced to 18 years' imprisonment and 18 strokes of the cane for robbery with hurt resulting in a female Japanese tourist's death at Oriental Hotel in 1994 and a consecutive sentence of life imprisonment with 12 strokes of the cane for kidnapping two police officers for ransom in 1996, which totalled up to 38 years' imprisonment and 30 strokes of the cane. His appeal for the two sentences to run concurrently led to the Court of Appeal of Singapore, which dismissed Abdul Nasir's appeal, to decide that it would be wrong to consider life imprisonment as a fixed jail term of 20 years and thus changed it to a jail term to be served for the rest of the prisoner's remaining lifespan. The amended definition is applied to future crimes committed after 20 August 1997. Since Abdul Nasir committed the crime of kidnapping and was sentenced before 20 August 1997, his life sentence remained as a prison term of 20 years and thus he is still in prison serving his 38-year jail sentence, which will possibly be reduced by one-third to 25 years and 4 months should he displayed good behaviour in jail. The appeal of Abdul Nasir, titled "", was since regarded as a landmark in Singapore's legal history as it changed the definition of life imprisonment from "life" to "natural life" under the law.
Notable people who were sentenced to natural life imprisonment in Singapore after 20 August 1997 were Muhamad Hasik bin Sahar; who killed a football player during a 8-member Salakau gang attack and being convicted of manslaughter (31 May 2001), Tony Anak Imba; who was convicted of murder for the robbery cum murder of an Indian construction worker (30 May 2010), Yong Vui Kong; a death row inmate who was initially sentenced to death for capital drug trafficking but later reduced his sentence to life imprisonment following the 2013 death penalty reforms in Singapore (14 November 2013), and Kho Jabing; a death row inmate and convicted murderer who, like Yong Vui Kong, also managed to reduce his sentence to life imprisonment following the reform of Singapore's death penalty laws but was once again sentenced to death merely two years later upon the prosecution's appeal against the commutation of his sentence (14 August 2013).
Despite the fact that a prisoner will be in jail for the rest of his natural life, the prison authorities will conduct an annual review of the prisoner's conduct once the prisoner had finished serving at least 20 years of his sentence, and they will assess the conduct through this review to see if the life convict was suitable for release on parole. If so, a remission order will be granted with certain conditions (like never get involved in crimes once the inmate is released). If not, he will continue to be in prison for a further indefinite period until the authorities became satisfied that he is eligible for parole. One instance of a life convict being released on parole in Singapore was Singaporean Vincent Lee Chuan Leong, a convicted kidnapper, who, together with his two accomplices - Zhou Jian Guang and Shi Song Jing - from China, kidnapped the 14-year-old teenage daughter of a wealthy car dealer on 9 September 1999, and within the same month, all three men were soon arrested and they were sentenced to life imprisonment in April 2000, with their sentences backdated to the dates of their arrests. According to a YouTube video, Vincent Lee, who was 33 years old when committing the crime, was currently released on parole from prison at the age of 54 since 22 June 2020 after serving a total of 20 years, 10 months and 9 days in prison with good behaviour, and is employed as a lorry driver. Unlike the United States and certain Western countries, the current life imprisonment laws in Singapore did not adopt a practice of life without parole, and the courts in Singapore had never imposed any consecutive natural life sentences on convicts in any case since after 1997.
Other than that, life imprisonment is the next highest punishment which Singapore adopts for certain crimes, as Singapore also applies the stiffer penalty of death to certain crimes like murder, possession of firearms and drug trafficking. It is also the maximum punishment for certain non-capital crimes like manslaughter (or culpable homicide not amounting to murder), criminal breach of trust by a public servant, attempted murder, causing grievous hurt with dangerous weapons, and many more. There is also a section of the Penal Code which slated that whoever was found guilty of committing attempted murder while serving a life sentence in Singapore, he/she would be automatically sentenced to death. They decreed that all those people who received fixed prison terms other than life imprisonment would have to serve their fixed jail terms concurrently with life imprisonment, unless their life sentences were reduced and thus made the fixed jail terms to run consecutively with the reduced sentence. Both the High Court and Court of Appeal in Singapore have the power to sentence an offender to life imprisonment; and the appellate court could either raise a fixed sentence to life, reduce a death sentence to life or reduce a life sentence to a fixed jail term. Not only that, the President of Singapore have the power to grant a death row inmate clemency and commute his/her death sentence to life imprisonment, but since 1965, there were only six successful cases when the President pardoned an inmate on death row in Singapore. The last case was in April 1998 when 19-year-old Mathavakannan Kalimuthu was spared from execution by then President Ong Teng Cheong, who offered him clemency and reduced Mathavakannan's sentence to life imprisonment.