Just as the first day of his trial was set to begin, the half-brother of a young mother who was killed five years ago in B.C. pleaded guilty in her murder.

Rachel Pernosky went missing from her home in Mission, B.C. in March 2013. A few days after her disappearance, her body was discovered at the bottom of an embankment in Chilliwack, B.C. She was just 18-years-old at the time of her death and had a one-year-old son.

Matthew Joseph Pernosky, Rachel’s estranged half-brother, was charged in connection with her death in June 2016.

On Monday, Matthew Pernosky pleaded guilty to second-degree murder in her death inside of a New Westminster courtroom. Rachel’s family learned of the planned plea just two days before the accused’s trial was to begin.

“We were all very relieved,” Rachel’s sister Brittany Pernosky told CTV Vancouver outside the courthouse. “My mom was emotionally exhausted. She was talking to me a few days before that saying she was just drained from the whole experience.”

Brittany Pernosky said the family wasn’t surprised by Matthew Pernosky’s plea.

“We always knew so it’s not like anything has changed,” she said. “You can only get so much closure in this kind of circumstance.”

For now, the family said they’re trying to focus on raising Rachel’s son Marco, who is six years old.

“He looks exactly like her," Brittany Pernosky said. "He's so good. He's so smart."

Police have never released a motive for the murder and without a trial the details may never be made public.

Matthew Pernosky is scheduled to be sentenced on June 21.

With a report from CTV Vancouver’s Breanna Karstens-Smith