Ecuadoran is charged; return sought

The announcement was the first official confirmation that the man who fled the United States hours after the bodies were discovered is believed to be the killer. Authorities said they have evidence including a bloodstained sledge hammer and Guaman’s fingerprints in the duffel bag that held the remains of Maria Avelina Palaguachi Cela and her son, Brian.

Plymouth District Attorney Timothy J. Cruz said talks were underway to return Guaman to the United States, despite Ecuador’s constitutional prohibition on extraditing its citizens. Cruz said he “fully expects’’ Guaman to face prosecution here.

“The legal jurisdiction is here, the witnesses are here, the physical evidence is here, and the many experts dedicated to analyzing that physical evidence at the State Police crime lab are here,’’ he said. “This community demands that the perpetrator of those crimes face justice here.’’

Guaman’s return would be a dramatic shift in a case that just days ago seemed destined to take place in Ecuador. Ecuadoran authorities, who are holding Guaman on charges of traveling under a passport with another name, had said Friday that they were cooperating with law enforcement in the United States to proceed with a murder trial there, using evidence gathered in the United States.

But officials with knowledge of the case said yesterday that the US Department of Justice had been in talks to persuade the Ecuadoran government. Cruz said officials from the Ecuadoran Embassy in Washington, D.C., are now indicating that Guaman could be returned “because he was responsible for the killing of a foreign citizen, namely Brian Palaguachi, who is a United States citizen.’’ Warrants seeking Guaman’s arrest on murder charges — and his return to the United States — were lodged with the international police agency Interpol and with the Ecuadoran government, Cruz said, adding that his office is awaiting a formal reply from authorities in Ecuador. “There hasn’t been any sort of refusal so far,’’ he said.

US Representative Stephen F. Lynch, a South Boston Democrat whose office has been in touch with officials in Ecuador to support Justice Department efforts, said it remains unclear whether an agreement could be reached that would overcome Ecuador’s constitutional ban. But he said Ecuadoran authorities should find a way around its prohibition, because Guaman’s case “is so egregious that they don’t want this overall policy to be poisoned by the facts of this case.’’

The Ecuadoran prosecutor who was preparing to try Guaman, Patricia Inga, said she is proceeding under the belief that he will remain in Ecuador. “We’ve already started an investigation against him because the victims’ families here have brought a complaint against him,’’ she said. Inga said that law enforcement officials in Massachusetts have not yet provided evidence including autopsy results and witness statements, as they had indicated they would.

“They said it would not be a problem,’’ Inga said.

If the case is tried in Massachusetts, Cruz said he would seek the maximum penalty, life in prison without parole, in sharp contrast to the maximum penalty of 25 years in jail that Guaman could receive in Ecuador.

Cruz said he “fully expects’’ Guaman to be prosecuted here.

“This is a heart wrenching case that has shocked communities both here and in Ecuador,’’ Cruz said. “The people of Ecuador and their government share our outrage over this murder. If convicted of these crimes, the penalty is life in prison without the possibility of parole. This man should not be able to evade exposure to that penalty by running away and hiding.’’

Some relatives of the victims who had feared Guaman would escape punishment in his native country said justice would be better served in the United States.

“He needs to face justice here, because here is where it happened, in America,’’ said Maria Emilia Palaguachi, sister of the dead woman. “For his crimes, he should pay here,’’ she said yesterday in her driveway in Brockton.

The grisly case unfolded Feb. 13, when authorities discovered the badly bludgeoned bodies in a dumpster near the Warren Avenue apartment that the victims shared with Guaman. Several hours later, Guaman, a roofer, boarded a plane for Ecuador at New York’s John F. Kennedy International Airport, using a passport with the name Segundo Castro.

Later, acting on a tip from Guaman’s estranged wife in the United States, Ecuadoran authorities arrested him on charges of using a fake passport.

Meanwhile, investigators in Brockton continued to piece together a case. In addition to the hammer and duffel bag, Cruz said the evidence linking Guaman to the killings includes clothing stained with blood, two rings identified as belonging to Guaman, and a pair of bloodstained sneakers found inside the duffel bag containing the victims’ remains. Guaman was last seen wearing sneakers, Cruz said. Investigators found human blood on Guaman’s nightstand.

There are other warrants out for Guaman’s arrest.

An arrest warrant was issued for Guaman in a 2007 assault and battery case in Milford, in which he allegedly punched a woman he was in a relationship with, grabbed her by the throat, and threatened to kill her and her infant daughter. The woman took out an abuse prevention order against Guaman, according to records from Milford District Court.

Guaman is also wanted on two felony warrants from Spring Valley, N.Y., on charges of kidnapping with malice and assault, and a pending case in Brockton stemming from an assault with a dangerous weapon charge in 2010, authorities said.

The bodies of the Brockton mother and son have been returned to Ecuador.

“Hopefully, later this year, I can go there and pay my respects,’’ said Manuel Tenezaca, Palaguachi-Cela’s brother-in-law.

Maria Cramer of the Globe staff contributed to this report.