The trial has begun for the first of three young people charged with murdering Baylee Wylie.

The 18-year-old Moncton man died a violent death, with his remains found in a burned out apartment just before last Christmas.

Devin Morningstar, along with Marissa Shephard and Tyler Noel, are facing first-degree murder and arson charges.

The first witness called was Helen Patria Mandy, who lived next door to the unit where Wylie’s body was found.

She said she heard loud arguments and screaming on the night of the Wylie’s death. She told the court she heard someone yelling, “You ratted to police and stole from us,” while another male voice responded, “I wouldn't do that, I love you guys.”

While retrieving her laundry in the basement of her unit, she testified hearing somebody begging for mercy in the next unit.

She believes there were four to five people in the neighbouring unit.

Mandy told the court Devin Morningstar was a frequent visitor of Shephard’s, and says many different people visited the house.

There were a lot of tears from Wylie's family throughout the testimony.

The Crown entered into evidence statements from first responders, investigators, and Morningstar's statements to police, as well as a number of physical exhibits.

According to an agreed statement of facts, Marissa Shephard and her young son were the main tenants of 96 Sumac Street, and investigators found a piece of packaging with Tyler Noel's name on it in the backyard.

Noel and Shephard will not go to trial for at least another year.

Morningstar’s trial is slated to last five weeks, though Justice John Walsh says it may finish sooner.

Testimony will resume Thursday morning.

With files from CTV Atlantic’s Cami Kepke.