A Christchurch Police officer who shot and killed a woman wielding a hunting knife, faced an unpredictable situation

Officers were called to Clyde Road in Bryndwr late on Wednesday, to deal with a man threatening himself and his partner with a knife.

An officer shot and critically injured the man, and then fatally shot the woman - when she threatened officers with the knife.

The man is in a critical but stable condition, following surgery.

Lance Burdett spent 22 years as a cop becoming the lead crisis negotiator.

He says Police do have other options like a taser, spray or a baton, but in the heat of the moment there are only split second decisions.