Rigoberto Lopez, 21, was taken into custody by New York City police on Saturday Police sources said Lopez, who is mentally ill, was charged on Sunday with murder and attempted murder after confessing to four separate attacks Subway rider, 67-year-old male, was wounded in stabbing on Friday before noon Twelve hours later, a man was fatally stabbed in neck, torso in southern Queens Two hours later, a woman, 44, died from stab wounds after she was found Minutes later, another man, 43, was wounded in stabbing in 181st Street station