Mathew Borges, 18, faces life in prison with eligibility for parole after 30 years
Mathew Borges
Credit: Paul Bilodeau/The Eagle-Tribune/AP

A Massachusetts teen was convicted of murdering his high school classmate whose decapitated body was found on the banks of a river in 2016, PEOPLE confirms.

On Tuesday afternoon, Mathew Borges, 18, was found guilty of first-degree murder after a nine-day trial in Salem Superior Court, according to an Essex County District Attorney’s Office press release.

Borges will be sentenced on July 9. He faces a sentence of life in prison with the possibility of parole after 30 years, since he was a 15-year-old minor when he committed the crime.

On Dec. 1, 2016, shortly before 3 p.m., Omar Medina was walking his dog behind his home along the Merrimack River in Lawrence, Massachusetts, when he made a grim discovery: “I thought I saw a dead body but I wasn’t too sure because it was missing some limbs,” he told jurors earlier this month.

The body was identified as Lee Viloria-Paulino, 16, a sophomore at Lawrence High School who had been missing since Nov. 18, 2016. His body had been decapitated and both of his hands were missing, according to police.

The day after Viloria-Paulino’s body was discovered, officials arrested Borges. He was charged with one count of first-degree murder with premeditation and extreme cruelty and atrocity.

Borges was accused of cutting off his classmate’s head and hands because he was allegedly jealous of the popular Viloria-Paulino, who was dating his ex-girlfriend, NBC10 Boston and other outlets report.

The Boston Herald reports prosecutors told jurors Borges sent his ex-girlfriend a text stating: “The next time you see me, look at my eyes because that’s the last time they’ll be like that. They’ll be dead.”

Twenty-four hours later, Viloria-Paulino was reported missing.

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Borges’ defense claimed at trial there was no physical evidence linking him to the killing.

“We’re disappointed in the verdict,” defense attorney Edward Hayden tells PEOPLE. “He got a fair trial. The prosecutors worked hard. The jury worked hard. We just disagreed with the verdict.”

According to the Boston Globe, Borges showed no emotion when his verdict was read aloud after a day of deliberations. The paper reports family members of Viloria-Paulino cried quietly.

“Nothing can bring Lee Paulino back to his family, who obviously love and miss him very much. It is my hope that this verdict gives them some comfort and peace,” Essex District Attorney Jonathan Blodgett said. “I wish to thank the jury for their service on this very difficult case. I also want to commend the entire prosecution and investigative team for their tireless pursuit of justice for Lee Paulino.”