DALLAS -- A man is dead after police said an off-duty Dallas officer shot and killed a man when she went into the wrong apartment.Police said it happened around 10 p.m. Thursday when the uniformed officer arrived to what she thought was her apartment after getting off work.At some point, she opened fire on a 26-year-old man inside, police said. He died at a hospital.The apartment complex is just two blocks from the Dallas police headquarters.The officer is now on administrative leave while the Dallas Police Department and the district attorney conduct an investigation.