A 30-year-old who has been charged with murder for pushing a woman in front of a moving subway train in New York reportedly told police that she was responsible for another subway death in October.

Witnesses said suspect Melanie Liverpool-Turner, 30, had been arguing with Connie Watton, 49, at the Times Square-42nd Street station on Monday. The two did not know each other, police said.

They were both standing on the downtown platform of the 1 train when Watton was shoved onto the tracks at around 1.20pm. She was pronounced dead on the scene shortly afterward, a police spokeswoman told Daily Mail Online.

A Metropolitan Transportation Authority worker said Liverpool-Turner looked 'proud' as she was led away by police officers moments later.

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The suspect Melanie Liverpool-Turner, 30, (pictured in pink top) was taken into custody. She has been charged with murder for pushing Connie Watton, 49, in front of a moving train

Watton was pronounced dead at the scene, and a MTA worker said Liverpool-Turner looked 'proud' as she was led away by police officers moments later

The two women were both standing on the downtown platform of the 1 train at the Times Square-42nd Street station at 1.20pm on Monday

A motive has not been established, but Liverpool-Turner told authorities she also pushed a German college student to her death last month at Union Square Station, the New York Post reported.

However officers think she is lying as the student is believed to have committed suicide after a breakup.

Witnesses at the time said they saw the 19-year-old jump in front of the train - however NBC reported that police are now revisiting the case.

Liverpool-Turner underwent a psychiatric exam at Bellevue Hospital after her claims, and police sources told the Post she has a history of bipolar disorder and schizophrenia.

Liverpool-Turner (pictured) told authorities she pushed a German college student to her death in October

Liverpool-Turner underwent a psychiatric exam at Bellevue Hospital after her claims, and police sources told the Post she has a history of bipolar disorder and schizophrenia

Liverpool-Turner is seen above in a photo she posted to Facebook. She had been on her way to Brooklyn to go shopping on Monday

The suspect's boyfriend, Olief Wilson, said Liverpool-Turner was taking the train on Monday to go shopping in Brooklyn.

It remains unclear whether Liverpool-Turner and Watton had been riding the same train, but police said they did not know each other.

Bystanders notified police officers on the platform after Watton was struck by the train, and Liverpool-Turner was led out of the station by several cops.

The suspect, left, with boyfriend Olief Wilson, is said to have a history of bipolar disorder and schizophrenia. Wilson said she was headed to some shops in Brooklyn on Monday

William Aubry, the police department's chief of Manhattan detectives, said investigators are still reviewing surveillance video and interviewing witnesses.

Aubry said: 'We have a lot of work to do...We are looking at video now and we're trying to capture the perpetrator and also the victim as they're entering into the train station.'

Liverpool-Turner had uploaded a passage on her Facebook page of 'The dangers of the Last Days' on September 11.

It says: 'In the last days there will be very difficult times. For people will love only themselves and their money.'

Liverpool-Turner shared this passage on her Facebook profile. She uploaded it on September 11

The suspect is pictured in the back of an NYPD police cruiser after being arrested on Monday

Emergency responders work at the scene to remove the victim's body from the tracks

NYPD police work at the scene after a commuter was pushed in front of a subway train

Many of those who saw the attack were visibly shaken.

'What happened here today is tragic,' Joseph Fox, chief of transit for the New York City Police Department, told reporters at the station.

One MTA worker told the Post: 'About five minutes ago, 20 police officers escorted her out. Her head was up — kinda proud of what she did.'

Another subway passenger Lindsey Ramirez wrote on Facebook that she 'saw a woman getting handcuffed, who looked like she didn't give a damn'.

Larissa Diaz, who works at a clothing store above the station, told AM New York she realized something had happened because 'there were so many people outside screaming.'

An investigation is ongoing.

Many of those who saw the attack were visibly shaken, and people immediately notified police officers on the platform

About three dozen police and other emergency officials responded to the incident

About three dozen police and other emergency officials responded to the incident at the station in midtown Manhattan.

The station, at the intersection of Seventh Avenue and 42nd Street, is one of New York's busiest transit stops.

Two hours after the incident, emergency responders were still working to remove the victim's body from the tracks.

The 1, 2 and 3 trains were delayed but service returned to its usual operation by Monday night.

'What happened here today is tragic,' Joseph Fox (center), chief of transit for the New York City Police Department, told reporters at the station

Dozens of people are hit by New York City subway trains each year, although most of the incidents are accidental

Dozens of people are hit by New York City subway trains each year, although most of the incidents are accidental, according to the Metropolitan Transportation Authority, which operates the system.

Last year, a woman was convicted and sentenced to 24 years imprisonment for fatally pushing a man into the path of an oncoming New York subway train in 2012.

The Times Square-42nd St station is New York's busiest, serving more than 66million riders every year, and on average 200,000 every day.

Ten subway lines converge on the station, as well as the shuttle to Grand Central Station.