Murphy, who has been outstanding for the Scorpions this season with two tries and three goals in his nine games, is a Wales A and junior international who started his rugby league at Bridgend Blue Bulls at under 15 level before working his way up to the senior side.
The 20-year old attended the open trials to finds Scorpions players this January and is the first player to have been specifically signed for the Scorpions to progress to a full Crusaders contract.
Wales coach and Crusaders assistant coach Iestyn Harris said: “We’ve been monitoring his performance for a number of weeks now. He deserves his chance to train in a Super League environment and we’re sure that this will help him develop as a rugby league player.”
“It is a great opportunity for Jamie to sign for the Crusaders and be coached by Brian Noble and Iestyn Harris in a full time environment. He has a whole heap of potential and I honestly believe he is a player who can play Super League in the not too distant future.
“He has a good pedigree having also played Wales under 20s rugby union at international level and he is someone we recruited at the Scorpions for 2010 as I thought he had real potential to adapt to League. He has put his best foot forward so far this season and due to the dual-registration agreement we will still continue to have access to Jamie when he is not selected to play in the Super League.
“This is another very good day for rugby league in South Wales and the potential of some of these youngsters down here is enormous. Jamie needs to knuckle down and work hard but his attitude is good and I am sure he will step up and make an impact in the next 18 months.”