My answer would have to be no. In Iran a woman can be put to death for sleeping with a member of the opposite sex for being raped as well as risk the death penalty if she (in self-defence) murders her would-be rapist. The age which a woman/girl can be sentenced to death in Iran is 9 for a man/boy it is 15. What happens if it was proven that the child was provoked? Called something which a reasonable adult would respond to, and as a response to that verbal slur, punch the person. Not expecting to kill him/her just hurt him. Could the child have been drunk suffering from some mental disorder. The defences mentioned would possibly in England and Wales reduce the crime of murder to manslaughter. The latter not carrying with it a life sentence.
Depending on the child’s age, they may not know what they are doing is wrong, and will not have as much knowledge about the world and society as the reasonable adult. Furthermore, countries which have the death penalty contravene Articles 3 and 5 of the Universal Declaration of Human Rights. Article 3 being the Right to Life. Article 5 No one shall be subject to torture, cruel, inhuman or degrading treatment.
Added to this is the Convention of the Rights of the child.
Article 37(a) State Parties shall ensure that: No child shall be subjected to torture or any degrading treatment or punishment. Neither capital punishment or life imprisonment without the possibility of being released shall be imposed for offences committed by persons below the age of eighteen.
Article 6(5) of the International Covenant on Civil and Political Rights: Sentence of Death shall not be imposed for crimes committed by persons below the age of eighteen.
Article 4(5) of the American Convention on Human Rights states: Capital Punishment shall not be imposed upon persons who, at the time the crime was committed, were under 18 years of age, or over 70 years of age.
The United States signed up to the Convention of the Rights of the Child in Feb 1995.
This means that should any person be sentenced to capital punishment in the United States for a crime committed when they where under 18. Then the United States will be acting in breach of it’s obligations under international law. Meaning that the United States (which includes any state or territory) would be breaking international law.