A judge sentenced two illegal Mexican immigrants to life in prison without the possibility of parole for the murders of three small children who were found nearly decapitated in slayings the judge said were done "to send a message."

Policarpio Espinoza, 24, and Adan Canela, 19, were convicted last month of first-degree murder and conspiracy to commit murder in the deaths of 8-year-old Lucero Espinoza and her 10-year-old male cousin, Alexis Espejo Quezada. They also were convicted of second-degree murder and conspiracy to commit murder in the death of 9-year-old Ricardo Espinoza Jr. He was Lucero's brother.

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"The deaths of these children stood as a message for others," Judge David Mitchell said before announcing the sentences. But the judge pointed out that it's still unknown what that message was and why the children were murdered in their family's apartment in May 2004.

Family members gave victim impact statements before sentencing that underscored the tragedy as well as the mysterious circumstances surrounding the murders. Espinoza is the children's uncle, and Canela is a cousin.

Noemi Espinoza Quezada, the mother of Lucero and Ricardo, spoke of the anguish the murders have caused the family, but she said she thought the trial was "unfair" and that she believed the evidence was insufficient.

"The truth is, I am not satisfied with what has been done," she said through a translator.

Prosecutors have repeatedly said family members are afraid to tell the truth about what happened.

Maria Andrea Espejo Quezada, the mother of Alexis, didn't defend the men, saying she wanted them to "tell us what was the motive of what they have done to the children."

Policarpio Espinoza declined to give a statement before being sentenced. Canela wept as he insisted he was innocent.

"I want to tell my family I didn't do this," he told the judge between sobs.

Canela said he loved his cousins and spoke of how he and the family had come to the United States to pursue dreams of better lives.

"Now look at what's been done to me," he said.

The fact that at least some family members were brought into the country by human smugglers, called "coyotes," has long hovered in the background of the complicated case. The family is from Tenenexpan, a town in the Mexican state of Veracruz. Their use of smugglers fueled speculation that the conditions under which the family entered the United States could have played a role in the murders.

Police have said they believe additional people likely played a role in the killings, possibly other family members.

Mitchell, before announcing the sentence, said there was evidence that some family members knew of the murders in advance "and did nothing to intercede."

Ricardo Espinoza Perez, the father of Lucero and Ricardo Jr., told The Associated Press in an interview last month that he doesn't believe smugglers he used could have been responsible. He said he didn't owe them money and the crimes happened about seven years after he and his family entered the country. He also said he believed someone with a grudge against Maria Andrea was involved.

Victor Espinoza Perez, a brother of Ricardo Perez and Policarpio, also spoke before sentencing, saying he was "100 percent convinced" that the men were innocent. He said he believed Maria Andrea knew who the killers were.

"Andrea knows who killed the children," he said in court. "She knows that very well."

She declined to comment on what he said.

The sentencing capped a long legal proceeding in a case that was so horrific that it sickened homicide investigators in a city with one of the nation's highest violent crime rates.

"No crimes shocked the community more than did these," Mitchell said.

It took prosecutors two trials to get convictions. The first trial ended in a hung jury in August 2005.

The evidence included two pairs of jeans with the children's blood and skin cells matching Espinoza and Canela's DNA. Prosecutors also presented a shoe worn by Espinoza with a small drop of Lucero's blood. They also had two bloody gloves with DNA links to the two men.

Christopher Lewis, a juror in the second trial who attended sentencing, praised the judge's decision. Lewis said he believes other people also played a role in the crimes. He also said he is still haunted by the gruesome photographs of the nearly decapitated children that were shown in court.

"You still have the images of the pictures in your head," Lewis said.