The Lower East Side mom accused of suffocating her 20-month-old son in a Midtown burger joint was mentally disturbed and under court supervision for the past four years.

Latisha Fisher, 35, was diagnosed to be paranoid-schizophrenic after she was arrested in 2011 on assault and weapons charges, and entered into an alternative sentencing program called CASES, The Daily News reports.

Court shrinks have been monitoring her since December of that year, and as recently as six months ago found her to be mentally fit and adjusting “very well to the demands of new motherhood,” says a report obtained by The News .

“She has been the poster child for an alternative to incarceration program,” the report said.

“This appears to be an instance where a mental health problem was the underlying cause of this tragedy,” Mayor Bill de Blasio told reporters.

Fisher was initially facing second-degree murder charges for the death of little Gavriel Ortiz-Fisher, but the NYPD has reclassified the case as a homicide.

RELATED: Latisha Fisher’s sad, emotional Social Media posts .

Her Facebook postings also portray a troubled woman. One of her most recent: “She’s banged up mentally and emotionally. Literally and metaphorically. But every day, she walks outside with a smile on her face because that’s who she is.”

September’s glowing CASES report was not the only one from the alternative sentencing program. In July of last year, a CASES psychiatrist found Fisher to be “psychiatrically stable and capable of remaining in the community.”

It’s unclear if CASES was in communication with the city’s child welfare agency.

The Administration for Children’s Services did have contact four years ago with Fisher, who has a 12-year-old son by a different dad, city officials said, but the mayor said there was no active case regarding Gavriel.

ACS promised an investigation and in a statement said: “We are orrified by this tragic death ...It is critical that all New Yorkers report any suspected signs of child abuse or neglect to help ensure we protect children at risk.”

The mayor said his administration is determined to do better regarding New Yorker’s mental health issues -- and the issue is a signature one for his wife, First Lady Chirlane McCray.

Fisher’s Facebook name was “Lola Honey” and in of several other sad postings was this: “True love and loyal friends are two of the hardest things to find.”

She lived with the baby’s dad, Luis Ortiz, who family members say is devastated by what happened.

When cops arrested her, a source told The News that Fisher “blamed the devil” for what happened.

“I put my hand over his mouth to put him to sleep,” she told them.