Murder is considered the most serious possible crime. State, federal, and international sentencing guidelines usually call for long prison sentences, life imprisonment or the death penalty for most murder convictions. Mandatory minimum sentences set by statute may supersede sentencing guideline calculations for murder, and remove any discretion the judge may have for imposing more lenient sentences.
Taking another person's life is one of the earliest recognised crimes, and guidelines for punishment of murder are found in the most ancient known legal texts. The Code of Hammurabai, approximately 1775 B.C., required the death penalty for murder. Laws from the time of Moses, recounted in the Old Testament of the Bible, call for the death penalty for deliberate murder, but require payment of fines and the killer's exile to specific cities of refuge for acts that today might be called manslaughter, or accidental homicide. Many factors established for murder sentencing in these ancient laws are still taken into consideration under modern murder sentencing guidelines.
Murder sentencing guidelines in most jurisidictions take into account considerations such as the reason for the murder, how it was committed, why it was committed, and any special characteristics of both the victim and the murderer, such as age, disability, or vulnerability. Courts may also consider the murderer's criminal history, and whether the death was related to other crimes such as a drug deal or robbery.
U.S. statutes require mandatory minimum sentences of life imprisonment or the death penalty for nearly all first-degree murder convictions in federal court. These mandatory minimum sentences apply even if sentencing guidelines recommend a lesser sentence. British law has required a mandatory minimum sentence of life imprisonment in all murder cases since 1965, but recent reforms have increased judicial discretion in sentencing all but the most heinous murders. Australia, Malaysia, Denmark, Taiwan and many other countries have mandatory minimum sentence laws for murder, though those minimums may range from five years to the death penalty.
Felony Murder Guidelines
Under U.S. federal law and the laws of most states and countries, a person may be charged with murder if someone dies in the midst of another felony crime, even if the defendant did not intend for that death to happen. For example, if someone is run over and killed by the getaway car in a robbery, all the robbers are guilty of felony murder. Felony murder sentencing guidelines are the same as those for first degree murder in nearly all jurisdictions.
First degree murder convictions result in long prison terms or mandatory life imprisonment or the death penalty in most jurisdictions worldwide. Statutes and sentencing guidelines for second degree murder, manslaughter, and accidental or negligent homicide, however, vary widely. U.S. federal sentencing guidelines are used for calculating sentences for voluntary and involuntary manslaughter, and judges have considerably more discretion in these sentences than in those for first degree murder.
Uncharged Murders as Relevant Conduct
Under U.S. federal sentencing guidelines, sentencing judges take into account all conduct relevant to the crime charged. Before a 2005 U.S. Supreme Court ruling in the case of U.S. v. Booker, judges could consider relevant conduct that pushed the resulting sentence far in excess of the sentencing guidelines recommendation for the crime of conviction. In many cases, defendants were sentenced for murders for which they had not been convicted, where judges found those deaths to be relevant conduct to the charged drug or other crime. The Booker case ruling declared it unconstitutional to enhance sentences beyond the sentencing guidelines' recommend range unless the facts of that conduct had been proven to a jury beyond a reasonable doubt.