Police say the community is safer without the pathetic gutless coward who murdered a Christchurch mother in front of her children

Nathan Boulter's been sentenced to life, with a minimum of 17 years without parole, for fatally stabbing Chantal McDonald in Parklands last July.

The 37-year-old has previous convictions, including the high-profile kidnapping and assault of a former partner on Great Barrier Island in 2011.

He refused to face the victim's family in court, appearing via audio-visual link.