MARRERO, La. — An off-duty police officer and a woman he was helping were shot and killed Friday in a New Orleans suburb, and agencies were searching for a man who had been involved with the woman, authorities said. Officer Michael Louviere, 26, of Westwego, was shot in neighboring Marrero, Jefferson Parish Sheriff Newell Normand told local media. He said dozens of officers from multiple agencies were searching for Sylvester Holt, 32, who had been romantically involved with the woman.