(INSIDE EDITION) -- A Massachusetts teen has been arrested for allegedly decapitating his classmate who went missing in mid-November.
Lee Manuel Viloria-Paulino, 16, was found alongside the Merrimack River with his arms and head separated from his body by a woman who was walking her dog on Thursday afternoon, according to reports.
Viloria-Paulino’s classmate, Matthew Borges, 16, was arrested Saturday morning after investigators reportedly found evidence linking him to the teenager’s death.
Authorities said Borges will be charged with first-degree murder as an adult.
“This was a horrific, horrific murder,” Essex District Attorney Jonathan Blodgett said.
Viloria-Paulino, a high school sophomore, was last seen on Nov. 18.
Borges visited Viloria-Paulino’s home once before his disappearance, according to reports.
His family reported him missing to police and posted on social media seeking information on his whereabouts, but they said Lawrence police didn't do their case justice.
"We disagree with the investigation of the police at the beginning," said Viloria-Paulino's grandfather, Gustavo Paulino.
The family said police treated the disappearance as a runaway case despite the family saying it was not.
“We are poor, we are Hispanic, they considered this a normal runaway case,” the teen’s grandmother, Ivelisse Cornielle, told the Boston Globe. “I told them from day one that it wasn’t.”
Many gathered at a vigil for the teen on Friday night.
"He was the best kid ever," Delaney Lora, a sophomore at the school told the Eagle Tribune "It's not fair."
Cornielle said her grandson may still be alive had police taken his disappearance more seriously.
“It’s my pain,” she said as she cried during a press conference.