SALEM (CBS) — A jury reached a verdict in the trial of 18-year-old Mathew Borges, who is charged with beheading Lee Viloria-Paulino in December 2016. Borges was found of guilty of first-degree murder.

He is accused of killing Viloria-Paulino, a classmate at Lawrence High School when they were sophomores in 2016. Viloria-Paulino was last seen alive on November 18, 2016, when Borges told police they smoked pot together. A dog walker found Viloria-Paulino’s body on the banks of the Merrimack River about two weeks later.

Borges will be sentenced on July 9.

Although he was tried as an adult, Borges was 15 at the time. He faces life in prison with the possibility of parole after 30 years. In 2013, it became unconstitutional to sentence a juvenile to life without the possibility of parole.

The jury of eight men and four women began deliberating Borges’s fate late Monday morning in Salem Superior Court.

Mathew Borges listens as a jury finds him guilty of first-degree murder (WBZ-TV)

Borges barely reacted when the verdict was read. “He just wanted me to call his mother. He’s taking it as well as can be expected,” said Defense attorney Ed Hayden outside court.

He added there is an automatic appeal to the decision. “I’ll file all the paperwork to get that done and then he will be appointed an appellate lawyer.”

During closing arguments, prosecutor Jay Gubitose said there was a “mountain of evidence” against Borges, including text and social media messages with friends and love interests and a notebook with entries seemingly premeditating the murder. Gubitose said Borges killed Viloria-Paulino because he was jealous Viloria-Paulino had spent time with his girlfriend.

Investigators said Borges stabbed the 16-year-old several times and cut his head off so the body would not be recognized.

Hayden said there was not enough evidence to convict his client and he questioned the credibility of Borges’ friends who testified against him. No DNA evidence was found at the crime scene.

Essex District Attorney Jonathan Blodgett said in a statement Tuesday, “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.”