Let me begin by deconstructing your claims (version of the question dating from 2022-05-15 16:53:47 UTC).
Firstly, the US has a relatively high homicide rate.
Okay, this sentence is factual and fine.
Secondly, the US might not have enough money to keep large numbers of murderers in prison, as running prisons costs money.
This statement only makes sense if you accept that capital punishment results in lower costs per prisoner than, say, a life sentence. However, that does not seem to be the case. The National Conference of State Legislators published an article in 2011 that stated:
Many state-initiated analyses—including reports from Michigan, New Mexico and South Dakota—have found administering capital punishment is significantly more expensive than housing prisoners for life without parole.
A study released last month found California has spent more than $4 billion on capital punishment since 1978, executing 13 criminals. That’s about $184 million more a year than life sentences would have cost.
At the very least, that disproves the assumption for the United States. Naturally, one would have to open the analysis separately for every country that continues to use capital punishment (e.g. Japan, Singapore, ...). However, recall that every person sentenced to death will
- be in prison or jail from their arrest to their trial (unless bail applies which may or may not be likely)
- be imprisoned during their trial (same caveat)
- be in prison while the decision is appealed
- be in prison while an execution day is set
- remain in prison until the execution is finally administered
High standards in legal systems will take a lot of at each of these steps as they value quality over speed. Thus, people spend many years, often more than a decade in prison before they are executed. On top of that, maintaining the infrastructure for executions costs money even though they are used relatively rarely. Therefore, this argument is likely to only hold true in places where legal protections are poor.
Therefore, the number of capital punishments given away by US courts should be high.
You obviously can't use absolute numbers because a country of 300 million inhabitants would necessarily have a different number than one of 3 million (unless that number is zero).
However, even the relative numbers might not compare. This is because homicide does not equal homicide. Before the death penalty was abolished in Germany, the law distinguished between murder and manslaughter where the former typically resulted in capital punishment while the latter was typically punished by prison time. (The distinction what was murder and what was manslaughter used to be intentional versus unintentional but was modified in 1941. Since then, the distinction was made along certain categories of evil (Mordmerkmale) causing a three-fold distinction between murder, intentional manslaughter and unintentional manslaughter. Murder remains punished with mandatory life imprisonment.)
Therefore, simply suggesting that a high homicide rate must result in a high death penalty conviction rate does not hold. Maybe every traffic accident casualty is considered a homicide in the statistic, the driver at fault prosecuted but the accident casualty rate particularly high due to lax safety standards. Maybe (and this probably applies specifically to the US) a high rate of gun ownership leads to a high rate of gun-related accidental homicides which a country with low rates of gun ownership such as Japan won't have. And so on.
Finally, the rate of capital punishment is a result of all convictions, not just those for homicide. Take for example Singapore, where drug-related offences are capital crimes: Since 2012 37 people have been executed of which 30 people were executed for drug-related offences – 81 %! If capital conviction rate for homicide were to double (i.e. 14 instead of 7 people, regardless of whether this were due to a higher homicide or a higher conviction rate), the total number of capital punishments would only rise by 13.5 %.
This is a reasonable expectation.
I hope I have shown that the expectation you have spelt out is not supported by the evidence you have provided.
However, this alone does not influence the question of why capital punishment attracts international criticism.
For one, capital punishment has experienced a general downward trend since the end of World War II. All internationally widely recognised European countries except Belarus and Russia have formally abolished capital punishment and Russia has not performed an execution since the 1990's. In many western European countries, there were high profile miscarriages of justice, see for example the United Kingdom with the cases of Timothy Evans and Derek Bentley. In the Federal Republic of Germany, capital punishment was outlawed when the consitution was adopted in 1949 following the Nazi dictatorship's use of the death penalty against dissidents. On the eastern side of the Iron Curtain, abolition was slower but did happen in most places by 2000 (e.g. the GDR formally abolished it in 1987, the last execution was in 1981 and the last execution of a civillian not for espionage was in 1971).
In addition, Europe-based NGO's such as Amnesty International strongly oppose the death penalty in all cases. Public opinion in most of Europe is considerably anti-death penalty.
The United Nations have regularly voted on resultions urging its members to abolish capital punishment.
Arguments against the death penalty include:
It is non-reversible. A life taken is a life gone. If justice was miscarried and an innocent person sentenced to life imprisonment, they can be released and reparations paid. If justice was miscarried and an innocent person executed, they cannot be revived.
In the United States, approximately 7800 people have been sentenced to death since capital punishment was reinstated in 1977, of which over 1500 have been executed but crucially 185 have been exhonerated between their sentence and execution, as per Wikipedia. This does not include cases where innocence was proven after the execution.
It cannot be shown to deter crime. Homicide rates are dependent on many factors but the possibility of being executed has little to no effect. On the contrary however, a thought experiment can be used to show how it might cause additional crime: Imagine a criminal has committed a crime which they know will likely result in execution. At this point, if they wish to survive they can take any means necessary, including intentional homicide of further people in their attempt to get away as they cannot possibly make their fate any worse.
It is discriminatory in practice. Even if homicide rates were the same among the disadvantaged and the advantaged, the advantaged have the means to pay for better lawyers, to formulate better appeals and to maybe ultimately get acquitted. This is a phenomenon that can be seen for all criminal convictions but (see the first bullet point) it carries more weight when a life is on the line.
It is costly. See above for arguments showing that inmates sentenced to death cost the state more than life imprisonment.
Fundamentally, it goes against the Basic Human Right to life. It is generally accepted in the western world that Basic Human Rights are not granted by any earthly power and that therefore no earthly power can revoke them. However, an execution is by its very nature a violation of one of the most fundamental rights, namely that to life and security of the person. Capital punishment as well as corporal punishments such as whipping are the only forms of punishment that violate this basic principle.
However, the most important reaon for international criticism of capital punishment can be summed up as:
European countries are both forerunners in abolition of the death penalty and in their population there is a relatively high support of abolition and abolitionist organisations. European countries are also relatively wealthy, powerful on the global stage, vocal in their support of Human Rights, and many. Therefore, there are a lot of well-heard voices that will speak up against capital punishment.