To answer your question Guevara01, Scott Phillips was the one who held Shauna hostage I think, and Kane helped. Scott came back to the Bay and held Flynn hostage for a short time while he demanded money off him. Tasha recognized Kane as he and Scott had committed at armed robbery at a petrol station somewhere, which is why Tasha was wary of Kane when she first arrived. Kane visited Scott in jail when Kane was on trial (the time when he and Kirsty left) and Scott promised to give evidence to help Kane in return for Morag to help get him out jail. However when the court case came, Scott didn't do as he promised.
I think that's correct, feel free to correct any errors.