Updated

The father of a 14-year-old Texas girl who was raped, sodomized and then strangled with a belt and shoe laces, wants to know why President Bush supports halting the execution of the Mexican national who confessed to killing his daughter and her friend.

"Our daughters are just pawns in a game that we have no control over," Randy Ertman, father of Jennifer Ertman, told FOX News. "What can I say to the president of the United States or the Supreme Court that would make any difference?"

Jennifer Ertman, 14, and her classmate, Elizabeth Pena, 16, were brutally raped and killed in 1993 after stumbling upon a gang. Jose "Joe" Ernesto Medellin, who was born in Mexico but spent much of his childhood in Texas, confessed to the killings and was sentenced to death. But 14 years later, Medellin still sits in a Texas prison cell as the White House argues that his conviction was flawed because Houston police failed to tell him of his right to seek help from the Mexican consulate.

Medellin's right to seek legal advice from Mexican diplomats is protected by the 1963 Vienna Convention, an international treaty that President Bush must follow under the U.S. Constitution, said Susan Gzesh, director of the human rights program at the University of Chicago.

"If the U.S. is going to disobey the obligations we've undertaken under the Vienna Convention, then other countries could retaliate," Gzesh said. "Bush is following the treaty."

The Supreme Court heard an oral argument Wednesday in the case of Medellin v. Texas, where the State of Texas presented arguments to counter those from the Bush administration and Medellin's attorney asked the court to set aside Medellin's conviction and death sentence and grant him a new hearing.

Medellin used a court-appointed attorney throughout his case but did not become aware of his right, as a Mexican national, to seek help from the Mexican consulate until after he was sentenced to death. That right extends from the 1963 Vienna Convention, of which the United States is a signatory, and the International Court of Justice found that the rights of Medellin, and 50 other Mexican-born U.S. inmates, were violated because they weren't informed of this right at the time their cases were being prosecuted.

The Bush administration was pulled into the case when Mexico sued the United States in 2003. The International Court of Justice ruled in Mexico's favor in 2004, ordering the United States to review the case. Bush wrote a presidential memo in 2005 saying that the U.S. would comply and order state courts to review the cases.

Bush later withdrew the United States from the Vienna Convention that gives the international court final say in international disputes. But that withdrawal did not change U.S. obligations to follow the treaty, Gzesh said.

The Supreme Court's ruling will determine whether the president has the power to order Texas state court to comply with the International Court's decision. The court will clarify presidential, congressional and court powers and what powers remain with the federal government versus the states.

"It is inexplicable that the president of the United States, our former governor, would turn his back on the families and on these victims and side with the world court and the Mexican government," said Dianne Clements, president of Houston's Justice for All, a criminal justice reform organization.

Texas executed 152 inmates while Bush was governor.

Medellin's crime, meanwhile, stands out as one of the state's most heinous.

On a summer night in 1993, Jennifer Ertman and her friend Elizabeth Pena, both students at Houston's Waltrip High School, took a shortcut home through a park from another friend's house when they encountered Medellin and seven other members of the Black and Whites gang.

Raul Villareal, 17, was being initiated into the gang, which required him to fight other gang members for several minutes. Following the ritual, the teens sat in the park drinking beer.

Around 11:30 p.m., as Ertman and Pena passed the young men, Medellin grabbed Pena and dragged her down a hill.

According to court testimony, Ertman was able to run away but heard Pena's cries and returned to help. The other boys grabbed Ertman, and for the next hour proceeded to rape, sodomize and beat the girls before strangling them.

The final act of brutality came when the girl's bodies were stomped on to make sure they were dead, court testimony shows.

The boys' were so brazen about their actions that one of them, Derrick Sean O'Brien, even turned up smiling on videotape taken by local news crews reporting at the scene.

The girls' bodies, meanwhile, were found four days later in a nearby woods.

O'Brien, Medellin and the other gang members were arrested after police received a tip from a brother of one of the gang members.

O'Brien told police that he and the other gang members raped both of the girls, and that Medellin strangled Ertman with a red nylon belt that was pulled so tight around her throat it snapped in two.

O'Brien, who also was suspected in the murder of another Houston woman, was convicted in 1994 and, after exhausting all of his appeals, was executed last year.

Three of Medellin's fellow gang members also received the death penalty. Two others had their death sentences commuted to life in prison in 2005 when the Supreme Court barred executions for those who were age 17 at the time of their crimes. Another defendant does not have an execution date.

Clements, who maintains contact with the families, said the group worked closely with Bush during his tenure as governor and she has no idea why the president took this position.

Bush's decision not only sets him apart from Texas, but from a conservative stance, Clements said.

"He has done a complete flip flop on this and turned his back on his very conservative base and is siding with the Mexican government over crime victims," Clements said.

Ertman said he feels betrayed by Bush's decision. Ertman shook Bush's hand when he was running for president, asking him if he remembered the girls and if he would keep their killers on death row. Bush said he would keep them on death row, Ertman said.

"He shook my hand and lied," Ertman said.

A California-based legal group filed a court brief on behalf of the family of one of the victims in support of upholding the death sentence for Medellin.

"The big battle is going to be over whether or not Bush's memo requires state courts to apply the rules of the treaty," said Michael Rushford, a spokesman of Criminal Justice Legal Foundation.

Click here to read the amicus brief.

Kent Scheidegger, the foundation's legal director, said regardless of the International Court's decision, Texas could legally proceed with the execution. The case, he said, needs to be over and Medellin's death sentence carried out.

"If Texas courts are required to follow international law, they can still go ahead with execution," said Scheidegger.

The Supreme Court is not expected to rule in the case until the Spring.