The sentence hearing for Isaiah Riel Rider, the 20-year-old man who admitted to killing a woman in her Ranchlands home in 2015, took place in a Calgary courtroom on Monday but there was a noticeable absence in the gallery.

Leslie Whitehead, the father of the 26-year-old victim, was the one who discovered Christa Cachene’s lifeless body in October 2015. Whitehead passed away Friday after suffering a heart attack.

A remorseful Rider, who has pleaded guilty to manslaughter in connection with Cachene’s death as, addressed the courtroom on Monday to apologize.

“I would like to express my heartfelt sorrow to Ms. Cachene’s family,” said Rider. The 20-year-old added that there is nothing he could say or do to make amends for his actions.

“What he said in court today was certainly remorseful and I believe it to be sincere and genuine because he’s been that was all along,” said Defence attorney Balfour Der. “His instructions were ‘I want to plead guilty’ which is the truest indication of remorse.”

According to the agreed statement of facts, Rider attended a party at Cachene’s home and an argument occurred. Cachene stabbed Rider in his lower back with a small knife and cut the teenager’s hand. Rider and Cachene exchanged punches and the 26-year-old woman was knocked to the ground. Rider proceeded to stomp on Cachene’s head and chest before dumping her body down the stairs into the basement.

An autopsy determined Cachene died as a result of multiple blunt force injuries and restricted blood flow to her head. Cachene, a mother of two, was pregnant at the time of her death.

Rider was arrested near Maskwacis nearly a week after Cachene’s death after he was identified as a suspect in a carjacking and a robbery at a residence. Rider has pleaded guilty to charges related to the offences.

Taking into consideration a reduction based on Gladue factors, the Crown is seeking an 18 year total sentence for Rider on the manslaughter, carjacking and home robbery convictions. The Defence is seeking a 15 year sentence.

“My client and us on the defence team acknowledge that what he did was very serious,” said Balfour Der, Rider’s legal representative. “It was a brutal beating of a young lady, she’s dead, and there were some serious offences that took place after it – an entry into a home, a carjacking. We had to acknowledge that this is all serious and 15 years is what we suggested was an appropriate sentence here which is a very significant sentence if you think about it being an 18-year-old.”

“It addresses denunciation, deterrence, but it also is not so long as to be crushing.”

Der says he expects Rider will benefit from incarceration.

“In custody, he’s actually going to get counselling. He’s actually going to get a chance to get an education. He’ll have a structured environment to live in and that will hopefully turn the corner for him because he’s otherwise a fairly bright, articulate young man.”

A Gladue report has been ordered for Rider to determine factors in his life as an Indigenous Canadian that may have contributed to his criminal history.

“He saw drug and alcohol abuse from being an infant. For his whole life he grew up in this environment where there was violence and there was substance abuse,” said Der. “It’s probably of little surprise that he ends up being someone who is addicted to alcohol and drugs and someone who used violence.”

Rider is scheduled to be sentenced on October 25.

With files from CTV's Ina Sidhu