JANESVILLE, Wis. (AP) – Rock County sheriff’s authorities have arrested a 75-year-old man in the shooting death last week of a woman who was his neighbor.        The sheriff’s office says the man was arrested Monday on suspicion of first-degree intentional homicide. He remains under guard in stable condition at UW Hospital in Madison.  Officers were called to a rural property Wednesday morning and found 59-year-old Christine Gestrich dead in a barn and the suspect with a self-inflicted gunshot wound in another outbuilding on the property.  The sheriff’s office says the man is the only suspect in the shooting.