Heartbreak for the family of a Christchurch woman, murdered in front of her children last July

Nathan Boulter's been sentenced to life, with a minimum of 17 years non-parole, for stabbing Chantal McDonald.

His past convictions include kidnapping and assault on Great Barrier Island in 2011.

McDonald's aunt Lyn says she feels overwhelming anger at Boulter , and his cold, emotionless demeanour.

She hopes he will be haunted by his actions for the rest of his life - and suffer as his victim did.