They have all had their fair share of successes and non-successes, as we have discussed in the past.
David Laidlaw also has his cases that remain unsolved. Some examples are:
Goran Nikolovski murdered in 2011 - there were POIs but no charges or prosecution
Link
Saso Ristevski murdered in 2011 - a Vic man was arrested six years later, extradited to NSW, then the charges were dropped as they no longer thought the Vic man was the murderer. They have never caught who they think committed the murder
Link
Jye McWatters murdered in 2015 - they have CCTV, had a primary POI, discovered more POIs, but no arrest
Link