The Constitution of the United States of Mexico (1917) at Art. 22 states:

The Constitution of the United States of Mexico (1917) at Art. 22 states: "The death penalty is prohibited for political crimes, and, in relation to other crimes, can only be imposed for treason during international war, parricide, first degree murder, arson, kidnapping, banditry, piracy and grave military offences."
The preceding offences were considered a threat to society when the Constitution was first introduced, and now have a symbolic function. The death penalty cannot be applied, in fact, because it is not included in any state or federal code.
In September 2003, the Mexican government moved to remove the reference to the death penalty from the Constitution, as the Commission of Government Policy on Human Rights Matters, led by the President of the Republic, decided to lend its support to initiatives presented in Congress towards this end.
The military penal code is the only part Mexico’s statutes that still effectively allows for the application of capital punishment. On March 31, 2004 President Vicente Fox, a firm abolitionist, sent the Senate a bill aimed at abolishing the death penalty under military jurisdiction and replacing it with prison terms ranging from 30 to 60 years. The Code of Military Justice allows the death penalty for serious crimes including treason, premeditated murder and arson, but executions have not been carried out since 1961, due to an informal tradition under which presidents commute capital sentences. Fox intervened in November 2003 to spare two soldiers sentenced to death by military tribunals for killing superiors. The Senate backed the president’s proposal in April 2004, but this had to be approved also by the Chamber of Representatives, dominated by the opposition, before it could become law. Should the lower house approve the bill, Mexico will become in effect completely abolitionist.
The last execution in Mexico took place in 1961, when a soldier was put to death for the murder of an officer. In 2001, in a landmark ruling, Mexico's Supreme Court said for the first time that citizens could be extradited as long as potential punishment did not include life prison terms or the death penalty. Mexican law has no provisions for either penalty.