She laughed so hard during her arraignment in Queens criminal court that Judge Gia Morris told her lawyer: "You're going to have to have your client stop laughing."
Defense attorney Dietrich Epperson said Menendez's behavior in court was no different from how she had been acting, and said his client didn't really think the proceedings were funny, according to Newsday. A call by The Associated Press to Epperson was not immediately returned Sunday. Menendez was held without bail and ordered to have a mental health exam.
Queens prosecutors said she pushed the 46-year-old India native to his death because she blamed "Muslims, Hindus and Egyptians" for the Sept. 11 terrorist attacks.
"I pushed a Muslim off the train tracks because I hate Hindus and Muslims ever since 2001 when they put down the twin towers I've been beating them up," Menendez told police, according to the district attorney's office.
Friends and co-workers said Sen, a native of Calcutta, was Hindu. He had lived in Queens for decades and was a graphic designer and copy shop owner. Sen was standing on an elevated platform of the 7 train that travels between Manhattan and Queens when he was shoved from behind as the train entered the station.
Witnesses told police a woman had been mumbling to herself and was sitting on a bench behind Sen until the train pulled in, then shoved him from behind. She then fled.
Police released a sketch and surveillance footage of a woman running from the subway station. Menendez was arrested after a passer-by saw her on the street and thought she looked like the wanted suspect. Witnesses identified her in a lineup and she was questioned by police, when she implicated herself, according to police and prosecutors.
Angel Luis Santiago, who used to work at the Queens building where Menendez's mother and stepfather live, said he was shocked by her arrest.
"It surprised me what she did," he said. "She never acted that way."
Menendez's next court appearance is scheduled for Jan. 14.
Sen was the second man to die after being pushed in front of a New York City subway train this month. Ki-Suck Han was killed in a midtown Manhattan subway station on Dec. 3. A homeless man was arrested and charged with murder in that case and is awaiting trial. He claimed he acted in self-defense.
Such subway deaths are rare, but transit officials said last week they would consider installing barriers with sliding doors on some subway platforms. Other cities including Paris and London have installed such barriers.