They said they are concerned about the welfare of the 49-year-old man who was last seen in the Val Plaisant area.
Mr Gilchrist is described as being 5’4″ and of medium build with white hair. The Police believe he was last seen wearing blue jeans, a dark blue Adidas zip up hoodie with light blue sleeves and a green khaki cap.
Anyone who has seen Mr Gilchrist or has information about his whereabouts is asked to contact the Police on 612612.