Of the 50 states that make up the United States of America, 38 have the death penalty.

Of the 50 states that make up the United States of America, 38 have the death penalty.
Federal law provides for 42 death-qualifiable offences, 38 of which relate to murder. Federal military law also provides for capital punishment.
Some states have laws that prescribe the death penalty for offences that do not involve the death of someone, including treason, espionage, kidnapping, hijacking and drug-trafficking.
California makes train sabotage, and perjury that has lead to a judicial execution, capital offences. A 1995 law in Louisiana allows death sentences for raping a child under 12.  Florida and Montana have laws making rape a capital offence irrespective of the age of the victim.
The last execution for rape in the US was carried out in 1964, and no one has been put to death for crimes other than murder since the Supreme Court re-instated the death penalty in 1976. 
US criminal procedure divides a trial for murder (or any other capital offence) in two separate stages. During the first stage a popular jury decides if the accused is guilty or innocent, and during the second the same jury, the judge or a group of 3 judges (depending on the state) weigh the mitigating and aggravating circumstances and decide on the punishment. Appeals are also divided into two phases: appeals concerning the guilt or innocence of the accused, and those that deal with the degree of punishment. The fact that the laws of an individual state provide life without parole, that is, without the possibility of the prisoner ever being freed, is considered a positive factor, because it makes the granting of clemency that commutes a death penalty to life without parole more probable.
The US Supreme Court has shaped the practice of the death penalty remarkably in recent years, issuing landmark judgments that have put more safeguards in place and took into account evolving standards of justice.
On January 9, 2002 the Supreme Court underscored its view that jurors choosing between a death sentence and a life term in prison should be told if the convicted killer has no chance of parole. The court ruled 5-4 that jurors at the 1996 trial of a convicted South Carolina killer, William Kelly, should have known that he could never be released if he was sentenced to life in prison. In this case the jury, that passed a death sentence on Kelly, was not instructed with regard to the life without parole option.
Even more far-reaching was the effect of two 2002 rulings barring the execution of mentally retarded people and ruling as unconstitutional death sentences issued by judges rather than juries. Both decisions could lead to a number of death sentences being commuted to life in prison.
On June 20, 2002, in Atkins v Virginia, the Supreme Court ruled 6-3 that executions of mentally retarded criminals are “cruel and unusual punishment,” violating the Eighth Amendment to the Constitution. In its decision, the majority cited a growing national consensus on the issue since the high court ruled in 1989 that such executions may be unacceptable. Between 1989 and 2002 the number of states that do not allow the execution of mentally retarded death row prisoners had grown from two to 18. This ruling led to the review of a number of individual cases and to legislative amendments. On June 24, in Ring v Arizona, the Supreme Court issued the second landmark ruling of the year, with a 7-2 majority declaring it is a violation of the right to trial by jury for a judge to impose a death sentence unless the jury has determined that factors exist justifying such a sentence.
‘What today's decision says is that the jury must find the existence of the fact that an aggravating factor existed,’ Justice Antonin Scalia said in a concurring opinion. Aggravating factors are those related to a crime that legally justify the imposition of a more severe penalty.
‘Those states that leave the ultimate life-or-death decision to the judge may continue to do so - by requiring a prior jury finding of an aggravating factor in the sentencing phase or, more simply, by placing the aggravating factor determination (where it logically belongs anyway) in the guilt phase,’ Scalia said.
The case involved Timothy Ring, an Arizona death row inmate. His death sentence and those of at least 125 other condemned Arizona prisoners were put on hold.
Montana and Indiana had changed their laws in anticipation of the ruling, and Delaware, Colorado, Idaho, Nevada, Nebraska and Arizona revised their laws after the Ring decision. Alabama and Florida remained the only two states that used judge sentencing before Ring v. Arizona that did not make changes to their law. Therefore a judge can still override a jury and pronounce a death sentence.
The ruling, passed in Ring v. Arizona, invalidated death sentencing laws in those states that left it to judges to determine whether a killer should be executed. However the Supreme Court did not make clear if its ruling should apply retroactively to everyone on those states’ death rows.
On the two-year anniversary of this ruling, the Supreme Court determined that its 2002 decision was a procedural rule and thus was not retroactive.
In their decision on Schriro v. Summerlin, on June 24, 2004, the justices ruled 5-4 against Arizona prisoner Warren Wesley Summerlin, sentenced to die more than 20 years earlier by a judge who later lost his job because of a drug problem.
This decision affected at least another 100 death row inmates - 85 in Arizona alone - who argued their death sentences had been improperly determined by judges, not jurors.
Besides the changes made in line with the Supreme Court rulings, a few US states also modified their capital punishment laws in other areas.
Indiana raised the age of eligibility for execution from 16 to 18 years, Pennsylvania legislated to allow post-conviction DNA testing, and California and Washington imposed more stringent standards on trial attorneys in an attempt to improve death penalty representation.
More safeguards in US death penalty law were added by the United States Congress, which, on November 5, 2003, passed a modified version of the Innocence Protection Act, which aims to help ensure eligible inmates access to DNA testing to establish their innocence and would authorize grants to the States to improve the quality of legal representation in capital cases. The House of Representatives approved, by a vote of 357-67, the Advancing Justice Through DNA Technology Act of 2003 that included a compromise version of the Innocence Protection Act as part of a larger DNA-related legislative package.
On June 25, 2003, the European Union and the United States signed an extradition treaty to boost cooperation in the fight against terrorism and in bringing suspects swiftly to trial. The agreement guaranteed for a suspect “the right to a fair trial” including the “right to adjudication by an impartial tribunal established pursuant to law.” The provisions underline the European Union’s categorical opposition to the trial of any of its nationals by special military tribunals such as those announced by Washington after the September 11, 2001 attacks. EU member states, that all oppose the death penalty, get assurance under the treaty that no EU citizen extradited to the United States, which enforces capital punishment, will be put to death.
On March 31, 2004, the International Court of Justice (ICJ) ordered the United States to “review and reconsider” the cases of 51 Mexicans facing execution. The Hague-based court ruled that Washington violated international law by not informing the 51 Mexicans that they were entitled to consular or legal help from their government as it must under the 1963 Vienna Convention. Mexico had taken the case to the ICJ on January 21, 2003. Mexico’s suit before the ICJ, also known as the World Court, concerned capital cases in California, Texas, Arizona, Arkansas, Florida, Nevada, Ohio, Oklahoma and Oregon.
 
Death sentences, executions, polls and moratoriums
2003 in the United States saw a decrease not only in executions, but also in death sentences passed and the total of death row inmates.
The US executed 65 people in 2003 compared to 71 in 2002. Of the 38 states that practice the death penalty in the US, 11 carried out executions - the lowest number since 1993.
As has been the case since the reintroduction of the death penalty in 1976, the majority of executions took place in southern states, 89% of the total in 2003. Texas was again the top executioner, with 24 people put to death (33 had been executed in 2002), 14 people were put to death in Oklahoma (double its 2002 tally) and North Carolina carried out 7 executions (up from 2 in 2002).
Oklahoma carried out the only execution in 2003 of a person who was under 18 years of age at the time of the crime. This execution was the 22nd such execution since 1976 - 13 minors were executed in Texas alone.
Fresh death sentences passed in 2003 were 143, down from 159 in 2002, and death row inmates diminished from 3,557 in 2002 to 3,504 in 2003, including 72 juveniles and 49 women.
Polls showed that capital punishment was becoming less popular in the US. An October 2003 Gallup poll found 64% in favour and 32% against. The gap is still large, but 64% was the lowest level of support for the death penalty in the last 25 years.
Various factors led to evolving attitudes on the death penalty issue. Main among these were the imperfections of the system, racial prejudice (in 2003 not one white person was executed for murder cases involving black victims only) class distinctions, and above all the judicial errors coming to light with increasing frequency. In 2003, 10 people were found to be innocent or wrongfully convicted, twice the number of the previous year. The total of people released from death row since 1973 had gone up to 115 by August 9, 2004.
In a historic move, on January 10, 2003, then Illinois Governor George Ryan emptied his state’s death row. He commuted the death sentences of 167 inmates to life in prison without parole and pardoned four men outright on the basis of innocence - they had been tortured into confessing crimes - after closely studying the Midwestern state’s death penalty system and finding it “rotten to the core”. This decision contributed significantly to decrease the nationwide death row population. In April 2003, after months of uncertainty, Ryan’s successor Rod Blagojevich upheld the moratorium that had been imposed by Ryan in January 2000, holding that the conditions for guaranteeing an error-free system were not yet in place. Ryan had imposed the moratorium to enable Illinois to study its death penalty system, a system that by January 2000 had already exonerated more people than it had executed since its-reinstatement in 1976.
The real fight over the death penalty was being fought in the state legislatures in 2003. Twenty of the 38 retentionist states in the federation were discussing moratoriums or abolition. The congressional debates centred mainly on doubts with regard to the application of the death penalty. North Carolina’s Senate approved a bill for a two-year moratorium on executions on April 30, 2003. However the bill, after strenuous opposition from the state’s district attorneys, did not get to a vote in the House of Representatives.
In early 2005, California interrupted a three-year de facto moratorium with the execution of Donald Beardslee. He was one of 640 people on California's death row, the largest in the nation, and the 11th inmate executed since California restored the death penalty in 1978.