Dempsie has been injury prone since he signed for Saints in 2003, having been released by Hibs. When he is fit he is a good defender, but sadly for Saints he was rarely fit. He missed the start of last season with injury, but then had a good run in the team, before getting injured in the summer and failing to play in all but a game against St. Johnstone.
Obviously the lack of first team football was annoying for Dempsie, who has been playing recently for the reserves. It was unlikely he would be offered a new contract in the summer, and his departure frees up a space on the Saints wage bill. There are rumours that this isn't the last piece of transfer activity at Saints this week.
Dempsie joins up with former team mate Eddie Annand, whilst fellow ex Saints Robert Dunn and Chris McGroarty recently left Dumbarton. His departure from Love Street means he'll miss the chance to face his former club in the cup in just over a fortnight.