Don't come to New Zealand if you are not 100% sure.
If crime was your only reason for considering to leave, then i suspect it was a very very serious crime incident.
I agree with both posts above. Regarding crime, we left SA only because of the crime, and we were never in a serious incident. Quite a few misses though. The lack of freedom to live as I had when a child, was a deciding factor for us. We have been gone 3 years, have lived in NZ for 18 months, and have never been happier. Even though we have no family here.
NZ does have its warts, like every country in the world, but they are warts that I can deal with, even if they are not removed.
Why NZ ? Why not Australia ? We had a choice of both, and chose NZ. However, Australia would be the place I would choose if I wanted to make more money, didn't mind the fires, heat and floods, didn't mind running out of water one day, and didn't mind supporting the Wallabies. Unfortunately, that wasn't enough for us.
We love New Zealand. That is personal though. Every person who has left, has their own story to tell. Every person deals with the immigration situation differently (except that we all stress !! ) and we have all settled down differently. For some it has been so easy, for others difficult. Some are happy, others not. It all depends on what you bring over with you.
So, as said above, if not 100 % certain, then don't move as you may well be carrying too much unwanted baggage over with you and this can lead to regrets.
Personally, I would be out of there in a heart beat, especially if my wife had been through these things. Ask yourself this question, what could happen next and are you ready to deal with that.