MONCTON, N.B. -- The murder trial of a young Moncton woman has been told the teenage victim was found dead in a burned home with "numerous injuries."

RCMP forensic investigator Cpl. Patrick Gould testified Monday at the trial of Marissa Shephard, 22, in the murder of 18-year-old Baylee Wylie of Moncton.

Gould told the jury he gathered evidence at a fire-charred house in a Moncton suburb on Dec. 17, 2015.

"The first and second levels were covered in soot. There was lots of water on the floor where firefighters had put the fire out," Gould told the court.

Gould said the body of a young male was in the middle of the living room floor, with a box spring on top of it. He said the body was on its back, wearing boxers and a t-shirt.

"He had numerous injuries on his neck, torso, legs and arms," Gould said.

Gould said there was a sofa in the living room heavily damaged by fire and the remains of a box spring.

Wylie's body was found by firefighters in a burned-out triplex at 96 Sumac Street, where he had been tied to a chair, beaten and stabbed more than 100 times.

Gould described a series of pictures he took at the scene as he gathered evidence.

The items included curtain rods, a plastic jug, a shard from a broken mirror, rubber gloves and a cleaning bucket.

Many appeared to have a red substance on them, he said, so they were examined for trace evidence such as bodily fluids and fingerprints.

He also described a couple of box-cutter type knives and screwdrivers that were seized.

Crown prosecutor Annie St. Jacques asked why screwdrivers would be seized.

"They are pointy objects that could be used as weapons," Gould replied.

Shephard has pleaded not guilty to charges of first-degree murder and arson with disregard for human life.

Twenty-one-year-old Devin Morningstar was found guilty of the same charges in November 2016 and is serving a life sentence.

Another man, 20-year-old Tyler Noel, pleaded guilty in May 2017 to second-degree murder and arson with disrespect for human life and was also given a life sentence.

Shephard was arrested March 1, 2016, and has been in custody ever since.

Shephard, with long brown hair and wearing a teal-coloured fleece top, listened intently to the testimony Monday.

A jury of seven men and seven women is hearing the trial, which may take a couple of months.