By BILL MILLER An Irving couple and their adult son appear to be victims of murder-suicide, police said Wednesday.Officers were called at 11:15 a.m. to the home in the 9000 block of Jasmine Lane, which is in the Valley Ranch neighborhood of Irving.Authorities were not ready to release the victims' names Wednesday afternoon, said Officer David Tull, police spokesman.Police, however, believe the victims were a man in his late 50s, a woman in her early 60s and their son who was in his 20s, Tull said."Indications are this is a double murder-suicide," Tull said.