Mandatory sentencing requires that offenders serve a predefined term of imprisonment for certain crimes, commonly serious or violent offenses. Judges are bound by law; these sentences are produced through the legislature, not the judicial system. They are instituted to expedite the sentencing process and limit the possibility of irregularity of outcomes due to judicial discretion. Mandatory sentences are typically given to people who are convicted of certain serious and/or violent crimes, and require a prison sentence. Mandatory sentencing laws vary across nations; they are more prevalent in common law jurisdictions because civil law jurisdictions usually prescribe minimum and maximum sentences for every type of crime in explicit laws.
 Mandatory sentencing laws often target "moral vices" (such as alcohol, sex, drugs) and crimes that threaten a person's livelihood. The idea is that there are some crimes that are so heinous, there is no way to accept the offender back into the general population without first punishing them sufficiently. Some crimes are viewed as serious enough to require an indefinite removal from society by a life sentence, or sometimes capital punishment. It is viewed as a public service to separate these people from the general population, as it is assumed that the nature of the crime or the frequency of violation supersedes the subjective opinion of a judge. Remedying the irregularities in sentencing that arise from judicial discretion is supposed to make sentencing more fair and balanced. In Australia and the United Kingdom, sentencing has been heavily influenced by judicial idiosyncrasies. Individual judges have a significant effect on the outcome of the case, sometimes leading the public to believe that a sentence reflects more about the judge than the offender. Subsequently, creating stricter sentencing guidelines would purportedly promote consistency and fairness in the judicial system. Mandatory sentences are also supposed to serve as a general deterrence for potential criminals and repeat offenders, who are expected to avoid crime because they can be certain of their sentence if they are caught. This is the reasoning behind the "tough on crime" policy.
 United States federal juries are generally not allowed to be informed of the mandatory minimum penalties that may apply if the accused is convicted because the jury's role is limited to a determination of guilt or innocence. However, defense attorneys sometimes have found ways to impart this information to juries; for instance, it is occasionally possible, on cross-examination of an informant who faced similar charges, to ask how much time he was facing. It is sometimes deemed permissible because it is a means of impeaching the witness. However, in at least one state court case in Idaho, it was deemed impermissible.
 Notably, capital punishment has been mandatory for murder in a certain number of jurisdictions, including the United Kingdom until 1957 and Canada until 1961.
 Throughout US history, prison sentences were primarily founded upon discretionary sentencing. Sentencing practices under this scheme were largely criticized due to the discretionary applications that judges used in sentencing. The assessment for sentencing was determined by three separate decisions by the judge in each specific case: (1) policy-based decisions, (2) fact-based decisions, and (3) applying such policy to such particular facts. In review of these policies regarding the applications of sentencing, the policy decisions are those that dictate what considerations should affect punishment. The second, which includes factual determinations is the process by which a judge determines whether to apply a particular policy to an offender. The third decision judges make in discretionary schemes is how to apply the sentencing policies to the particular facts. By the mid-twentieth century, mandatory sentencing was implemented.
 Their actions would result in punishment as a part of the sentencing process, regardless of the type of weapon in question. The first individual waved the weapon, but the second waved and inflicted force. Therefore, the two individuals in question regarding the same crime could receive two separate sentences.
 Overtime, the United States had changed implementation of sentencing laws. Beginning in the early 1900s, the United States began to assess its role on the use of drugs, their purpose and the responsibilities within the law. During this time in 1914, opiate drug use outside of medical purpose was prohibited. In 1930, marijuana reached the same platform as opiates, with its use being prohibited. This led to stiffer regulations, even though the use of marijuana was not believed to evoke violent tenancies as previously suggested in earlier years, but this level of awareness had not reached public acknowledgment. In turn, sentencing guidelines in reference to drug use further, as well as they did to sales consisting of opiates primarily (heroin and morphine). The sentencing guidelines applied to the use and sales of drugs. However during this time, discretionary sentencing was still practiced. Therefore, there were different sentences for individuals who were guilty of using prohibited drugs compared to those who sold drugs.
Mandatory sentencing and increased punishment were enacted when the United States Congress passed the Boggs Act of 1951. The act made a first time cannabis possession offense a minimum of two to ten years with a fine up to $20,000; however, in 1970, the United States Congress repealed mandatory penalties for cannabis offenses. With the passage of the Anti-Drug Abuse Act of 1986 Congress enacted different mandatory minimum sentences for drugs, including marijuana.
 The Anti-Drug Abuse Act of 1986 profoundly affected the US legal system into contemporary times. The act led to a Drug Free initiative regarding an individual's employment, a Drug Free workplace and certification requirements for employers, and a Drug Free environment for those who receive government benefits (such as for low-income housing recipients). The act further addresses interventions regarding illegal sale of imported drugs, such as the ability to confiscate assets for those guilty of distribution. The act also implemented the first laws surrounding money laundering, which also led to the exposure of professional dealers. Those found guilty of distribution were sentenced as outlined.
 Separate from each state's own courts, federal courts in the United States are guided by the Federal Sentencing Guidelines.  (See War on Drugs for more information about US drug laws.) When a guideline sentencing range is less than the statutory mandatory minimum, the latter prevails. Under the Controlled Substances Act, prosecutors have great power to influence a defendant's sentence and thereby create incentives for defendants to accept a plea agreement. For example, defendants with prior drug felonies are often subject to harsh mandatory minimums, but a prosecutor can exercise discretion to not file a prior felony information. Then the mandatory minimum will not be applied.
 Safety Valve was created in 1994 to reduce mandatory sentencing for drug offenders under the following provisions:
 In October 2011, a report was issued to assess the impact of United States v. Booker mandatory minimum penalties on federal sentencing by the United States Sentencing Commission.[clarification needed]
 In 2013, United States Attorney General Eric H. Holder, Jr. announced that the Justice Department would follow a new policy restricting mandatory minimum sentences in certain drug cases.  Prosecutions dropped, drug enforcement agent morale dropped, and fentanyl and heroin overdoses soared, reported The Washington Post in 2019.  In Alleyne v. United States (2013) the Supreme Court held that increasing a sentence past the mandatory minimum requirement must be submitted by a jury and found factual beyond a reasonable doubt. It increases the burden on the prosecutor to show that the sentence is necessary for the individual crime by requiring that a mandatory minimum sentence be denied for a defendant unless they fulfill certain criteria. Attorney General Holder held that the charges placed on an individual should reflect the uniqueness of the case and consideration in assessing and fairly representing his/her given conduct. This purpose is to prevent recidivism.
 Criminal justice advocates in the United States argue that mandatory minimum sentences are a major cause of the removal of the "bottom income half to quartile" of its population from the general public. As part of police targeting and surveillance and often harsh sentencing, mandatory sentencing often is proposed as "fairness" by those unfamiliar with the penal systems in the US. Mandatory sentencing still has not been linked to other areas such as racial profiling, a 700% increase in US prison incarceration rates, zero tolerance and prison growth at the expense of employment, housing, education, family support and quality of life.
 The U.S. state of Florida has a 10-20-Life mandatory sentence law regarding sentences for the use of a firearm during the commission of another crime, and many PSA posters were created after the law was passed, which coined the slogan "Use a gun, and you're done." It gave a minimum mandatory sentence of 10 years if the offender pulls a gun, but does not fire a shot, 20 years if at least one shot is fired, and 25 years to life if the offender shoots someone.
 In 1996, 12-month mandatory sentencing laws around third offence home burglary were introduced by Western Australia through amendments to the 1913 Criminal Code. In 1997 mandatory sentencing was introduced to the Northern Territory in Australia. The three strikes and out policy raised incarceration rates of indigenous women by 223% in the first year. The incarceration rate for men rose by 57% and 67% for indigenous men.[citation needed] The mandatory sentencing laws sparked debate of the laws being discriminative (indirectly) as indigenous people are overrepresented in the crime statistics in the Northern Territory.[citation needed]
 New South Wales has two mandatory sentences currently. The Crimes Amendment (Murder of Police Officers) Bill 2011 introduced mandatory life sentence without parole for a person convicted of murdering a police officer. Also, the Crimes and Other Legislation (Assault and Intoxication) Amendment 2014 introduced mandatory minimum sentencing of 8 years for alcohol fuelled acts of violence, as a response to the cases of king hit assaults in Sydney. These laws were championed by NSW Premier Barry O'Farrell largely due to the wide media coverage of similar cases, in particular the case of Kieren Loveridge who killed Thomas Kelly.
 Life imprisonment is mandatory for murder in Queensland, South Australia, and the Northern Territory. Life imprisonment is only mandatory in the other states for aircraft hijacking or with a minimum non-parole period of 20 years (25 years in South Australia and the Northern Territory) if a criminal is convicted of the murder of a police officer or public official.[citation needed]
 Australia also has legislation allowing mandatory prison sentences of between five and 25 years for people smuggling, in addition to a fine of up to $500,000, and forfeiture and destruction of the vessel or aircraft used in the offence.
 In 2017, the government of Victoria introduced a "two-strike" policy, with a minimum six-year jail sentence for repeat violent offenders.
 Victoria also has a mandatory 10-year minimum sentence for people convicted of killing someone in a so-called "one punch" attack.[citation needed]
 Denmark has mandatory minimum sentences for murder (five years to life) and regicide (life in prison § 115), deadly arson is punished with imprisonment from 4 years to life, and for an illegal loaded gun one year in state prison.
 The state of Florida in the United States has a very strict minimum sentencing policy known as 10-20-Life, which includes the following minimums: 10 years' imprisonment for using a gun during a crime, 20 years' imprisonment for firing a gun during a crime, and 25 years' imprisonment in addition to any other sentence for shooting somebody, regardless of whether they survive or not.
 In Canada and Ireland, life imprisonment is mandatory for murder if committed, at the time of the offence, as an adult. Parole ineligibility periods vary, but under Irish and Canadian law, are not less than 7 and 10 years, respectively.
 In New Zealand, life imprisonment is mandatory for murder. Murders with certain aggravating factors have a mandatory 17-year non-parole period, instead of the default 10 years for life imprisonment. Since 2002, judges have the ability to overrule mandatory sentences where they would be deemed "manifestly unjust", such as in cases involving mercy killings and failed suicide pacts.
 In Germany, murder for pleasure, sexual gratification, greed or other base motives, by stealth or cruelly or by means that pose a danger to the public or to facilitate or cover up another offense is mandatorily punished by life imprisonment.
 In Ireland, Acts of the Oireachtas specify a mandatory sentence of life imprisonment for murder and treason, and mandatory minimum sentences for various lesser offences. A mandatory minimum sentence may be truly mandatory or may be presumptive, giving a judge discretion to impose a lesser sentence in exceptional circumstances. Mandatory sentences have been challenged on grounds that they violate the separation of powers required by  the constitution, by allowing the Oireachtas (legislature) to interfere in the judicial process. In 2012 the Supreme Court ruled that the mandatory sentence of life imprisonment for murder was constitutional. However, in 2019, it ruled that a mandatory minimum sentence had to apply for all offenders, not for certain classes of offenders. It struck out a sentence of 5 years for possession of a firearm, because it was truly mandatory only for a second offence, whereas it would have been presumptively mandatory for a first offence. A mandatory sentence for a second offence of drug trafficking was struck out in 2021 for similar reasons; the conviction was upheld but the sentence referred back to the Circuit Court for reconsideration.
 In the United Kingdom, upon conviction for murder, the court must sentence the defendant to life imprisonment. The law requires that courts must set a minimum term before they become eligible for parole. For this purpose a number of "starting points" are in place that give guidance to a judge to impose a sentence in each different case of murder. There are currently five "starting points" for murder in England and Wales, namely: 12 years' imprisonment for cases of murder committed by a person under 18; 15 years' imprisonment for all "other" cases of murder committed by a person over 18; 25 years' imprisonment for cases of murder where a person over 18 uses a knife or other weapon at the scene; 30 years' imprisonment for cases of murder with "particularly" high aggravating factors, such as those that involve the use of a firearm or explosive, or a murder in the course of committing another offence such as robbery or burglary; and a whole life order, in cases that involve such "exceptionally" high aggravating factors, such as the murder of two or more persons, or the murder of a child following abduction or with sexual/sadistic motivation, meaning the person will never become eligible for parole.
 The United Kingdom currently also has three more mandatory minimum sentences for certain offences, namely: a minimum of 7 years' imprisonment for a person over 18 convicted of trafficking, supplying or producing Class A drugs for the third or subsequent time; a minimum of 5 years' imprisonment (for a person over 18) or 3 years' imprisonment (for a person aged 16–17) for possession, purchase, acquisition, manufacture, transfer or sale of a prohibited firearm or weapon for the first or subsequent time; and a minimum of 3 years' imprisonment for a person over 18 convicted of a domestic burglary for the third or subsequent time.
 In 1994, California introduced a "Three Strikes Law". This state is known for fully enforcing laws and is considered most severe in comparison to other states. The Three strikes law was intended to reduce crime by implementing extended sentencing to deter repeated offenders. This consideration further restricts one's ability to commit new crimes.  Similar laws were subsequently adopted in most American jurisdictions.
 However, California's "Three Strikes Law" is clearly outlined for all, especially those who are subjected to such sentencing.
 strike (1)
 strike (2)
 strike (3) 
 A similar "three strikes" policy was introduced to the United Kingdom by the Conservative government in 1997. This legislation enacted a mandatory life sentence on a conviction for a second "serious" violent or sexual offence (i.e. "two strikes" law), a minimum sentence of seven years for those convicted for a third time of a drug trafficking offence involving a class A drug, and a mandatory minimum sentence of three years for those convicted for the third time of burglary. An amendment by the Labour opposition established that mandatory sentences should not be imposed if the judge considered it unjust.
 According to figures released by the British government in 2005, just three drug dealers and eight burglars received mandatory sentences in the next seven years, because judges thought a longer sentence was unjust in all other drug and burglary cases where the defendant was found guilty. However, in 2003 a new "two strikes" law was enacted (effective from April 4, 2005), requiring courts to presume that a criminal who commits his second violent or dangerous offence deserves a life sentence unless the judge is satisfied that the defendant is not a danger to the public. This resulted in far more life sentences than the 1997 legislation. In response to prison overcrowding, the law was changed in 2008 to reduce the number of such sentences being passed, by restoring judicial discretion and abolishing the presumption that a repeat offender is dangerous.
 Australia's Northern Territory in March 1997 introduced mandatory sentences of one month to one year for the third offence regarding property and theft. They were later adopted by Western Australia.
 Concerning US federal prisons, Barbara S. Meierhoefer, in her report for the Federal Judicial Center stated: "The proportion of black offenders grew from under 10% in 1984 to 28% of the mandatory minimum drug offenders by 1990; whites now constitute less than a majority of this group. This is a much more dramatic shift than found in the federal offender population in general."
 According to the Statistical Overview of Mandatory Minimum Penalties presented in October 2011, "[o]f all offenders convicted of an offense carrying a mandatory minimum punishment and who remained subject to that penalty at sentencing, 38.5 percent were Black (n=4,076), 31.8 percent were Hispanic (n=3,364), and 27.5 percent (n=2,913) were White."
 Although exceptions such as the safety valve are authorized, demographics associated with race relevant to mandatory sentencing continue to show. "Hispanic offenders received relief from applicable mandatory minimum penalties at the highest rates, with rates of 65.9 percent in fiscal year 2000, 57.7 percent in fiscal year 2005, and 55.7 percent in fiscal year 2010. Other Race offenders had the next highest rates (52.8% in fiscal year 2000, 53.1% in fiscal year 2005 and 58.9% in fiscal year 2010). Black offenders consistently had the lowest rates (45.7% in fiscal year 2000, 32.8 percent in fiscal year 2005, and 34.9% in fiscal year 2010). White offenders received relief at 60.3 percent in fiscal year 2000, 42.5 percent in fiscal year 2005, and 46.5 percent in fiscal year 2010."
 Opponents of mandatory sentencing point to studies that show criminals are deterred more effectively by increasing the chances of their conviction, rather than increasing the sentence if they are convicted. In a hearing of the House Judiciary Committee, Judge Paul G. Cassell, from the United States District Court for the District of Utah, described mandatory sentencing as resulting in harsh sentencing and cruel and unusual punishment, stating that the sentencing requirements punish defendants "more harshly for crimes that threaten potential violence than for crimes that conclude in actual violence to victims". A hearing in 2009 heard testimony from the American Bar Association which stated that "Sentencing by mandatory minimums is the antithesis of rational sentencing policy". In 2004 the association called for the repeal of mandatory minimum sentences, stating that "there is no need for mandatory minimum sentences in a guided sentencing system." A 1997 study by the RAND Corporation found that mandatory minimums for cocaine offenses were not cost-effective in regards to either cocaine consumption or drug crime.
 Some judges have expressed the opinion that mandatory minimum sentencing, especially in relation to alcohol-fueled violence, is not effective. In R v O’Connor, the High Court of Australia gave the opinion that when an offender is intoxicated, there will likely be a change in their personality and behaviour, which will then affect their self-control; that, while an offender may commit an act which is voluntary and intentional, it is not something that they would have done in a sober state. Intoxication is not a justification for criminal behaviour, nor (in most jurisdictions in the U.S. and Commonwealth) a legal defence; but since an intoxicated person's decisions are less likely to be shaped by rational assessment of consequences than those of a sober person, deterrence is likely to be less effective for intoxicated people.
 Research indicates that mandatory minimum sentencing effectively shifts discretion from judges to the prosecutors. Prosecutors decide what charges to bring against a defendant, and they can "stack the deck", which involves over-charging a defendant to get them to plead guilty. Since prosecutors are part of the executive branch, and the judicial branch has almost no role in the sentencing, the checks and balances of the democratic system are removed, thus diluting the notion of separation of powers. Opponents of mandatory sentencing argue that it is the proper role of a judge, not a prosecutor, to apply discretion given the particular facts of a case (e.g., whether a drug defendant was a kingpin or low-level participant, or whether sex offender registration is an appropriate measure for a given crime and offender). When prosecutors apply discretion, they tend to invoke sentencing disparities when choosing among a variety of statutes with different sentencing consequences. In addition to fairness arguments, some opponents believe that treatment is more cost-effective than long sentences. They also cite a survey indicating that the public now prefers judicial discretion to mandatory minimums.
 In 2015, a number of United States reformers, including the ACLU, the Center for American Progress, Families Against Mandatory Minimums, Koch family foundations, the Coalition for Public Safety, and the MacArthur Foundation, announced a bipartisan resolution to reform the criminal justice system and reduce mandatory sentencing laws. Their efforts were lauded by President Obama who noted these reforms will improve rehabilitation and workforce opportunities for those who have served their sentences. In their arguments they noted that mandatory sentencing is often too harsh of a punishment and cripples someone's livelihood for minor crimes.
 In 2019, then presidential candidate Joe Biden unveiled his criminal justice reform plan which would eliminate mandatory minimum sentences.