US asked to prod Ecuador on suspect

In a letter sent last week to Attorney General Eric H. Holder Jr. and Secretary of State Hillary Rodham Clinton, Cruz said Ecuadoran officials have failed to grant repeated entreaties to send Luis A. Guaman to Brockton, where he has been indicted on first-degree murder charges in the bludgeoning deaths of his 25-year-old housemate, Maria Avelina Palaguachi, and her 2-year-old son, Brian.

Guaman fled to his native Ecuador hours after the bodies were found in a trash bin in February. Ecuadoran officials say they cannot extradite Guaman because their constitution forbids extradition of their own citizens. Instead, officials have offered to prosecute him there.

Cruz ruled out that option, calling it “dangerous and offensive,’’ and said the United States and Ecuador have an extradition treaty that could be used to return Guaman. He said US officials should consider sanctions against Ecuador if officials refuse to return him.

“What kind of message does that send to the next person who potentially kills another US citizen, another baby, and then is allowed to sneak out of our country in the darkness of night and go to a country that refuses to abide by our treaty with their country?’’ Cruz said in a phone interview yesterday. “I hope they will provide him to us, to allow us to try our case here. It’s never too late to do the right thing.’’

Cruz asked federal officials to file a formal extradition request for Guaman, since weeks of informal talks with Ecuadoran officials have proved fruitless.

Laura Sweeney, a Justice Department spokeswoman, said the department will review the letter and work with state and local officials to bring Guaman back.

The State Department did not respond to requests for comment yesterday.

Guaman, a 41-year-old roofer who lived for years in Massachusetts, is in jail in Ecuador on charges of possessing a fraudulent passport, which he allegedly used to flee the United States.

He will face trial tomorrow for those charges in the city of Cuenca, and a three-judge panel could issue a verdict on the same day. He faces up to six years in jail for the passport charge, prosecutors said.

In Cuenca yesterday, the top prosecutor Hernan Flores said Ecuador cannot disobey its own constitution, the highest law of the land. “Whatever the case, he has to be judged in Ecuador,’’ Flores said.

But Flores said he was eager to prosecute Guaman and lamented the lack of cooperation from US officials, who he said have not responded to Ecuador’s repeated requests to send evidence so that prosecutors could file murder charges against Guaman there. He said Ecuador even conducted its own autopsies on Palaguachi and her son when the bodies were sent to her homeland for burial.

“It’s grave, the lack of collaboration from prosecutor to prosecutor,’’ Flores said. “It shouldn’t be this way.’’

Flores said his office would fight to keep Guaman in jail. “We’re not going to let him go,’’ he said.

Cruz has the support of Senators Scott Brown and John F. Kerry and Representative Stephen F. Lynch, who have reached out to government officials in hopes of having Guaman returned to Massachusetts for prosecution.

Brown suggested that the Guaman case could become an issue when the United States considers renewing the Andean Trade Preference Act, which grants trade benefits to Ecuador and other nations. Brown pointed out that the US government ended Bolivia’s benefits under the act in 2008, saying the nation was not doing enough to eradicate drugs.

“I believe that Ecuador’s unwillingness to return the fugitive Guaman is very troubling and warrants serious scrutiny of whether renewal of its ATPA benefits is warranted,’’ he said in a letter to Clinton and US Trade Representative Ron Kirk last week. “Until Guaman is returned to Massachusetts, I know that the Guaman case will be at the forefront of my mind if unanimous consent or my vote is requested for renewal of ATPA preferences for Ecuador.’’

But others were more skeptical.

Bruce Zagaris, a Washington attorney who specializes in international criminal law, said returning Guaman would subvert Ecuador’s highest law. He said it seems especially unlikely given a recent diplomatic rift between the two countries. Last month, Ecuador expelled the US ambassador for allegedly discussing police corruption in a diplomatic cable revealed by the WikiLeaks website.

“Putting pressure on Ecuador to do something against its constitution, especially when the pressure comes from a country that you don’t have friendly relations with, and when you just expelled its ambassador, there’s no way that’s going to happen,’’ Zagaris said.

Zagaris said it is not uncommon for a nation to refuse to extradite its own citizens — France is one example. In some cases, he said, prosecutors from the United States have traveled to other countries, such as Mexico, to prosecute fugitives.

Still, Cruz said he was hopeful.

“All I’m trying to do is get a man back here who’s charged with murder to give him his day in court,’’ he said. “I’m just a lawyer from Brockton. That’s all I know.’’

Maria Sacchetti can be reached at msacchetti@globe.com. Follow her on Twitter at @mariasacchetti.