A Canadian man has admitted to killing his estranged half-sister on the first day he would be tried for her shocking murder.

According to the Terrace Standard, Mathew Pernosky, 33, entered a surprise guilty plea for the March 2013 slaying of Rachel Pernosky, 18. The mother to a then-1-year-old boy vanished from her British Columbia home and was reported missing on March 16. Her body was discovered three days later at the bottom of an embankment in Chilliwack.

“We were all very relieved,” Rachel’s sister Brittany Pernosky told reporters outside the courthouse, according to CTVNews.

Brittany said the family was informed over the weekend of Matthew’s plans to plead guilty.

“My mom was emotionally exhausted. She was talking to me a few days before that saying she was just drained from the whole experience,” she said.

Early on in their investigation, police said Rachel’s death was not random and identified her half-brother as a person of interest. Matthew was arrested in connection with Rachel’s murder on June 27, 2016. Reports indicated that details of how the young mom was killed and a motive were never released to the public.

In pleading guilty to second-degree murder, two counts of indignity to a body are expected to be stayed at Matthew’s sentencing hearing, which is scheduled for June 21. He

“We always knew so it’s not like anything has changed,” Brittany said of her relative’s recent guilty plea.

“You can only get so much closure in this kind of circumstance.”

[Featured image: Rachel Pernosky/Handout]