A teenager in Massachusetts convicted of beheading a classmate has been sentenced to life in prison - with chilling diary entries from his journal used in court as evidence.
Mathew Borges, 18, was found guilty of first degree murder for the 2016 killing of then 16-year-old Lee Manuel Viloria-Paulino.
Borges, who was 15 at the time of the murder, would apparently get jealous when his ex-girlfriend Leilany Dejesus talked to other boys - including Viloria-Paulino, who Borges became so angry about, he had to get escorted out of the school cafeteria by a teacher.
The family of Viloria-Paulino grew concerned on 18 November 2016 when he went missing. It turned out he had gone out with Mathew that night, and looked like the two had made up.
Viloria-Paulino's corpse was found two weeks later with no head and no hands. As well as being decapitated, he had been stabbed 76 times.
While the defence said there was no physical evidence linking Mathew to the crime, with no murder weapon, no DNA, no blood and no fingerprints to prove that Borges was behind the killing.
However, prosecution argued there was still a 'mountain of evidence' elsewhere.
They referred to text messages he'd sent, along with journal entries he made that outlined the night of the murder.
Reading like a twisted plan, one said: "Go chill with him in his crib alone... bring duffel bag, wear bags on shoes, wear clothes you don't care about."
Another ex-girlfriend, 18-year-old Stephanie Soriano, also read text messages she said he sent her before the murder, saying he often spoke of his 'demons'.
Soriano said he sent her one message that read: "I think of killing someone and I smirk.
"It's all I think about every day but I control myself... I like the sound of it - the idea of causing pain in someone getting in my way or causing me pain.
"I see people I don't like [and] that comes to mind. I'm going insane."
Borges was found guilty of first-degree murder in May this year, when it was determined he'd committed the act with 'deliberate premeditation and extreme atrocity and cruelty'.
He was then sentenced in July, where defence tried to point out that he was a child at the time of a murder, and had potential to be rehabilitated.
But the victim's heartbroken mother Katiuska Paulino said in a statement to the court that he should 'never have the opportunity to kill again'.
Paulino said: "From the moment the news became public all we have heard is an outpouring of sentiments echoing the facts that we knew to be true."
She continued: "[Lee] was a sincere, loving, responsible, charismatic, and altruistic young man on the verge of seizing life and many, many goals.
"Every day we struggle with the fact his life was cut too short.
"We drove ourselves crazy trying to make sense of what had been done.
"With him gone we feel like we can't breathe... Lee Manuel... was our oxygen."
The judge sentenced Borges to two life sentences and ordered that he would serve a minimum of 30 years to life in prison before the chance of parole.
Paulino added: "There is no sentence I can impose that will bring back Lee Paulino, or that will answer the questions we all have about how this happened, and how a 15-year-old boy could kill a friend in this manner."