Seven months ago, Latisha Fisher’s troubled life seemed to have gotten back on track. It had been a long climb to stability since September 2011, when Fisher, a diagnosed paranoid schizophrenic, attacked an acquaintance with a steak knife, slashing the woman’s head, arm and ear.

Last September, officials proclaimed her a "poster child" for a program offering rehabilitation to mental-health patients instead of prison time, court documents show, after she enrolled in community college and repeatedly tested clean for illegal drugs.

But something went wrong. On Monday, Fisher, 35 years old, was huddled in a bathroom stall of 5 Boro Burger on Sixth Avenue in Midtown Manhattan, cradling the unconscious body of Gavriel Ortiz-Fisher, her 20-month-old son. She said to distraught restaurant employees that the devil had told her to smother him, authorities said.

On Tuesday, police charged her with the boy's murder.

Investigators are piecing together Monday’s events through interviews and restaurant surveillance footage. Fisher was captured on video pushing her son’s stroller into the burger restaurant around 12:43 p.m. She ordered food and a drink and fed her son bites as he played.

Then they went to the bathroom. Nearly half an hour later, they hadn’t emerged. Customers heard banging from inside the bathroom, and when restaurant workers opened the door, they saw the child lying still in his mother’s hands, foaming at the mouth.

Gavriel was rushed to Bellevue Hospital Center, where he was pronounced dead shortly after arriving, authorities said.

Fisher told emergency responders “the devil made her do it” and that she had “put him to sleep,” motioning with her hands that she had smothered the boy, according to a law-enforcement official.

On Tuesday night she remained in custody and under evaluation at Bellevue Hospital’s psychiatric ward, pending arraignment. It wasn’t clear if an attorney had been assigned to her case.

The city’s Administration for Children’s Services was contacted about the homicide Monday night and is also investigating the case, a spokesman said.

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