WASHINGTON, June 15 -- A gunman posing as a police officer killed a senior Democratic Minnesota state lawmaker and her husband on Saturday in an apparent "politically motivated assassination," and wounded a second lawmaker and his spouse. Democratic House leader Melissa Hortman, 55,and her husband, Mark, were killed at their home, while state senator John Hoffman, 60, and his wife, Yvette, were wounded in a separate shooting at their home, authorities said. Police said a "manifesto" listing lawmakers throughout the US was found in a vehicle linked to the suspect, who was at large. "An unspeakable tragedy has unfolded in Minnesota," governor Tim Walz said Walz said. Hortman was the top House Democratic leader in the state Legislature and a f...