Detective Constable Breen is 24 going on - 24. Following in his father's footsteps becoming a detective was the logical thing to do. Sam has followed the system and achieved Detective Constable status with relative ease if not huge amounts of effort. Being a detective has up until now seemed like a good job more than a calling. Something he found easy and, because his father was one, something familiar.
However, upon meeting Mike Shepherd, Breen is forced to up his game and in doing so is inspired to do better work. One day he hopes to be more like Mike i.e. less by the book and more intuitive. But that comes with miles on the clock and something he can't put his finger on - he calls it ‘the Shepherd Factor'. Breen hopes by working closely with Mike some of the Shepherd magic will rub off on him.
When off duty Breen plays rugby for the local club team the Brokenwood Cheetahs. He enjoys a good night out when he can and strives to be considered as one of the lads. He has an on again/off again relationship with a woman called Roxy.