CHILLING TEXT AND AUDIO MESSAGES sent to classmates in 2016 are coming back to haunt Mathew Borges as he goes on trial for the murder and beheading of a fellow classmate at Lawrence High School.

Borges was 15 at the time of Lee Manuel Viloria-Paulino’s murder, but he is being tried as an adult because prosecutors believe the crime was premeditated and committed with extreme atrocity and cruelty.

On the first day of the trial in Salem District Court, Borges’s attorney argued his client is guilty of breaking in to Viloria-Paulino’s home along with other kids to steal video games and clothing – but not murder. He said prosecutors have no motive, no murder weapon, no tool used to remove Viloria-Paulino’s head and hands, no blood, no fingerprints, and no DNA. He said the text messages displayed by prosecutors contain no evidence of a crime.

Prosecutors said in their opening statement that Borges told his fellow robbers that he had killed Viloria-Paulino. The prosecutors also said they found a book in Borges’s room in which he plotted the murder, writing about the need to bring along a duffel bag, gloves, and bags to cover his shoes.

Prosecutors suggested jealousy may have been a motive. They put Leilany DeJesus, a former girlfriend, on the stand, who testified that Borges became angry and yelled at her when he found her eating lunch at school with Viloria-Paulino. DeJesus also admitted, however, that Borges apologized the next day and that she never mentioned jealousy in her conversations with police investigators.

Borges’s most recent girlfriend, Stephanie Soriano, read out loud messages she sent to Borges in 2016 while prosecutor Jessica Strasnick read the responses of Borges. A lot of it was teenage relationship talk, accentuated with emojis.

But in November 2016 the messages took a dark turn. “I think of killing someone,” he said in one message. “I like the sound of it, the idea of causing pain. It’s all I think about every day but I control myself. I see people I don’t like [and] that comes to mind. I’m going insane.”

Days later, on Nov. 17, 2016, the day before prosecutors say Borges killed Viloria-Paulino, he messaged Soriano and asked if his eyes looked dead.

“Yours look dark but they wanna shine again,” she typed back.

Borges told her he was thinking thoughts that made him “shiver.” He then sent her a voice memo. “Eyes that are dead are scary…makes you think about what that person has done. What they’ve been through. What they’ve seen. Eyes that don’t shine, that are full of darkness,” Borges said in the recording. “It’s just sad. It’s like these people are different. They’ve done things that make them lose their humanity. Like they have no soul. They just have big black pupils.”

He would have dead eyes soon, Borges told Soriano.

On November 20, 2016, Borges texted Soriano, asking her to delete their conversation. A week later he texted her again, saying “keep everything I tell you to yourself.”

On December 3, 2016, Viloria-Paulino’s body was discovered on the Lawrence riverfront.