New York City police deployed hundreds more officers to the subway system on Saturday after a string of stabbing attacks apparently targeting the homeless left two people dead. New York City Police Commissioner Dermot Shea said the first attack happened on Friday morning when a 67-year-old man was stabbed by a masked assailant at the West 181st Street station in upper Manhattan. That victim is recovering in the hospital. Late on Friday, a man was found stabbed to death on the A train at Far Rockaway-Mott Avenue station in Queens, police said. Two hours later, a 44-year-old woman was discovered unconscious with stab wounds on an A train at the 207th Street station in Manhattan. She was pronounced dead at a hospital. In a fourth incident early Saturday, a 43-year-old man was stabbed back at the West 181st Street station. He underwent surgery and is in a stable condition, police …