Edgar Tamayo was convicted of the January 3, 1994 shooting death of Houston police officer Guy Gaddis and and was executed last month in Texas . Thousands of mourners poured out to see the burial of the Mexican man put to death by lethal injection in Texas last month, a move that has sparked diplomatic tensions between the U.S. and the central American state. Friends and relatives carried the coffin of Mexican Edgar Tamayo to the cemetery in his home town of Miacatlan, Morelos state, amid an outpouring of grief from local residents. The 46-year-old Mexican was controversially executed in Texas less than two weeks ago for the killing of a Houston police officer in 1994, despite outrage from human rights groups and last minute appeals from his lawyers for clemency on the grounds that Tamayo was mentally disabled. The case saw the unusual intervention of the U.S. Secretary of State, John Kerry, who had repeatedly urged the Texas Attorney General Greg Abbott to delay Tamayo's punishment, saying it 'could impact the way American citizens are treated in other countries.' Abbott and the Harris County district attorney opposed postponing what was the first execution this year in the ultra-conservative American state. Some 16 people were executed in Texas in 2013. The Mexican government also sharply criticized the decision, saying failure to review Tamayo's case and reconsider his sentence would be 'a clear violation by the United States of its international obligations'. Tamayo was found guilty of shooting 24-year-old Houston policeman Guy Gaddis 20 years ago. Tamayo’s lawyers, the Mexican government and rights groups all say Tamayo was denied a fair trial because he failed to receive consular help, something which they say broke international law and could have helped him avoid the death sentence. Scroll down for video . Relatives of the mentally disabled Tamayo carry his coffin aloft as mourners look on . Outpouring of grief: Local mourners watch as friends carry the coffin of Tamayo, whose death has strained ties between Mexico and the U.S. Tamayo's lawyers had appealed for his death sentence to be commuted because the 46-year-old Mexican was mentally disabled . Human rights groups and his lawyers say Tamayo was denied consular help which could have changed the outcome of his trial . The Mexican government condemned the execution, saying failure to review Tamayo's case and reconsider his sentence would violate the U.S.'s international obligations . A woman hugs the mother, right, of Mexican Edgar Tamayo before his burial in the city of Miacatlan, Morelos state . People attending a farewell tribute for Edgar Tamayo on February 2 in Mexico sit on or peer through a fence . U.S. Secretary of State John Kerry urged the Texas Attorney General Greg Abbott to delay Tamayo's punishment . A man plays a trumpet by the coffin of Tamayo, who was was sentenced to death in Harris County in November 1994 . His lawyers also argue that Texas governor Rick Perry and the state's Attorney General Greg Abbott failed to honor a pledge to review Tamayo's case . The parents, sister and nieces of Edgar Tamayo stand around his coffin before his burial . Legal assistance guaranteed under the Vienna Convention could have uncovered evidence to contest the capital murder charge or provide evidence to keep Tamayo off death row, they said. His lawyers also argue that Texas governor Rick Perry and Abbott reneged on a promise to review Tamayo’s case as ordered by the International Court of Justice in 2004. Tamayo's attorneys previously appealed to a federal court in Austin, Texas, for an injunction against  Perry and the Texas Board of Pardons and Paroles, which he appoints. The board could have recommended Perry grant clemency, but it's an action they rarely take. A judge rejected that lawsuit last month.
Thousands line streets of Mexican city for burial of Edgar Tamayo .
He was executed by lethal injection last month for killing a policeman .
His lawyers say he didn't receive a fair trial .
Edgar Tamayo was convicted of the January 3, 1994 shooting death of Houston police officer Guy Gaddis and and was executed last month in Texas . Thousands of mourners poured out to see the burial of the Mexican man put to death by lethal injection in Texas last month, a move that has sparked diplomatic tensions between the U.S. and the central American state. Friends and relatives carried the coffin of Mexican Edgar Tamayo to the cemetery in his home town of Miacatlan, Morelos state, amid an outpouring of grief from local residents. The 46-year-old Mexican was controversially executed in Texas less than two weeks ago for the killing of a Houston police officer in 1994, despite outrage from human rights groups and last minute appeals from his lawyers for clemency on the grounds that Tamayo was mentally disabled. The case saw the unusual intervention of the U.S. Secretary of State, John Kerry, who had repeatedly urged the Texas Attorney General Greg Abbott to delay Tamayo's punishment, saying it 'could impact the way American citizens are treated in other countries.' Abbott and the Harris County district attorney opposed postponing what was the first execution this year in the ultra-conservative American state. Some 16 people were executed in Texas in 2013. The Mexican government also sharply criticized the decision, saying failure to review Tamayo's case and reconsider his sentence would be 'a clear violation by the United States of its international obligations'. Tamayo was found guilty of shooting 24-year-old Houston policeman Guy Gaddis 20 years ago. Tamayo’s lawyers, the Mexican government and rights groups all say Tamayo was denied a fair trial because he failed to receive consular help, something which they say broke international law and could have helped him avoid the death sentence. Scroll down for video . Relatives of the mentally disabled Tamayo carry his coffin aloft as mourners look on . Outpouring of grief: Local mourners watch as friends carry the coffin of Tamayo, whose death has strained ties between Mexico and the U.S. Tamayo's lawyers had appealed for his death sentence to be commuted because the 46-year-old Mexican was mentally disabled . Human rights groups and his lawyers say Tamayo was denied consular help which could have changed the outcome of his trial . The Mexican government condemned the execution, saying failure to review Tamayo's case and reconsider his sentence would violate the U.S.'s international obligations . A woman hugs the mother, right, of Mexican Edgar Tamayo before his burial in the city of Miacatlan, Morelos state . People attending a farewell tribute for Edgar Tamayo on February 2 in Mexico sit on or peer through a fence . U.S. Secretary of State John Kerry urged the Texas Attorney General Greg Abbott to delay Tamayo's punishment . A man plays a trumpet by the coffin of Tamayo, who was was sentenced to death in Harris County in November 1994 . His lawyers also argue that Texas governor Rick Perry and the state's Attorney General Greg Abbott failed to honor a pledge to review Tamayo's case . The parents, sister and nieces of Edgar Tamayo stand around his coffin before his burial . Legal assistance guaranteed under the Vienna Convention could have uncovered evidence to contest the capital murder charge or provide evidence to keep Tamayo off death row, they said. His lawyers also argue that Texas governor Rick Perry and Abbott reneged on a promise to review Tamayo’s case as ordered by the International Court of Justice in 2004. Tamayo's attorneys previously appealed to a federal court in Austin, Texas, for an injunction against  Perry and the Texas Board of Pardons and Paroles, which he appoints. The board could have recommended Perry grant clemency, but it's an action they rarely take. A judge rejected that lawsuit last month.
Gaddis and and was executed last month in Texas . burial of the Mexican man put to death by lethal carried the coffin of Mexican Edgar Tamayo to the rights groups all say Tamayo was denied a fair rights groups and his lawyers say Tamayo was