In the 20 plus years I've been living and traveling to and from PNG the law and order situation has never changed, the circumstances only change.
One distinct element with regards to the crime in PNG is that the rascals/criminals in just about all cases don't generally have the intent to harm or kill their victims, all they want are the material things. When people do get injured or killed, it usually involves a robbery that goes wrong or it's related to tribal warfare or paybacks.
Touch wood I've only been directly affected by 2 robberies, 1 was a holdup and the other was a break and enter into a house. In the case of the holdup I only lost my wallet which was actually voluntarily returned as the rascals accidentally mistakenly targeted me for someone else, in the house break in we lost a lot of personal goods whilst we were sleeping upstairs, didn't even know the place had been done over until I went downstairs and realised that the doors were open and the place had been ransacked.