SALEM, Mass. — A Massachusetts teenager convicted of fatally stabbing and then decapitating a high school classmate has been sentenced to life in prison.

Eighteen-year-old Mathew Borges, of Lawrence, will be eligible for parole in 30 years under the maximum allowable sentence handed down on Tuesday by Superior Court Judge Helene Kanzajian.

A jury convicted Borges in May of first-degree murder in the November 2016 killing of 16-year-old Lee Manuel Viloria-Paulino. Viloria-Paulino’s decapitated body and head were found along the banks of a river by a dog walker.

Prosecutors say Borges was jealous the victim had spent time with a girl he liked.

Under Massachusetts law, a first-degree murder conviction carries a life sentence without the possibility of parole for adults. But parole eligibility must be added if the crime was committed as a juvenile.