Melanie Liverpool-Turner, a 30-year-old woman, has been arrested by the police.
The woman was arrested for pushing another woman, 49-year-old Connie Watton, in front of a moving subway train in New York.
According to NY Daily News, witnesses said Liverpool-Turner, had been arguing with Watton, at the Times Square-42nd Street station on Monday.
Police said the two women did not know each other.
Police spokeswoman said they were both standing on the downtown platform of the 1 train arguing when all of a sudden, Watton was shoved onto the tracks at around 1.20pm and pronounced dead on the scene shortly afterwards,
Metropolitan Transportation Authority worker said Liverpool-Turner looked 'proud' as she was led away by police officers.
One witness said she saw Turner get arrested. She said: 'About five minutes ago, 20 police officers escorted her out'. 'Her head was up, kinda proud of what she did.'
Liverpool-Turner lied and told authorities she pushed a German college student to her death last month, even though police concluded the 19-year-old had committed suicide.
Liverpool-Turner underwent a psychiatric exam at Bellevue Hospital, and police sources told the New York Post she has a history of bipolar disorder and schizophrenia.
William Aubry, the police department's chief of Manhattan detectives, said investigators were reviewing surveillance video and interviewing witnesses to determine a motive.