(AP) - Three young children found dead in a bed after their mother called police claiming she killed them appeared to have been drowned, although one's throat was cut and all showed signs of possible poisoning, a homicide detective said.

A medical examiner's preliminary findings Monday confirmed that drowning was the likely cause of the deaths of the girl, 6, and two boys, 5 and 1, who were found by police called to a two-story apartment building in an impoverished neighborhood in New Cassel in central Nassau County. Homicide detectives noted, however, that the exact cause would have to await the results of toxicology tests.

The mother, Leatrice Brewer, 27, was at the Nassau University Medical Center for injuries she suffered from jumping out of their second-story apartment window, police said. Her arraignment was postponed until Tuesday on the advice of doctors, a spokesman for District Attorney Kathleen Rice said.

It was not immediately known if Brewer, who some neighbors described as troubled, was represented by an attorney.

Lt. Michael Fleming, commander of the Nassau homicide squad, said Brewer called 911 shortly before 9 a.m. Sunday, telling an operator "that she killed her babies. She even spelled her name to the 911 operator."

The woman told the officers she had killed her children, then jumped out of her window and was locked out of the apartment, Fleming said.

When officers went inside the apartment, they found Jewell Ward, 6, Michael Demesyeux, 5, and Innocent Demesyeux, 1, in a bed in their nightclothes, with the youngest in the middle.

"They almost looked as though they were sleeping," Fleming said. "It almost looked like they were cuddled up together for the night."

Fleming said foaming around the victim's mouths and noses could be a symptom of drowning or could indicate the children were poisoned with a toxic substance. He also said the 6-year-old girl's throat was cut.

"We did recover bleach and some caustic substances," he said, noting toxicology tests would be conducted as part of the autopsies.

Brewer, who had six arrests - two felonies and four misdemeanors - on her record dating to 2000, was described by some as troubled, including two men who identified themselves as the children's fathers and said they had fought in vain to have the children removed from Brewer's custody.

"Whenever I tried to get my daughter, Family Court wouldn't let me," said Jewell's father, Ricky Ward. "The courts wouldn't hear me out. I blame this on Leatrice Brewer and Family Court."

Innocent Demesyeux, the father of the two boys, told reporters he had been battling Brewer for custody for more than a year.

One neighbor, Cornisha Robinson, said she saw Brewer pushing an empty stroller in the street last week and wondered where the children were.

"She neglected them," Robinson said. "She used to leave them in the house all the time by themselves."

Relatives, however, saw things differently.

"My sister's not crazy," Brewer's brother Robert McCord said. "She's not ballistic. This is a shock to all of us."

A cousin, Robin Brooks, said Brewer is "a woman that needed help. She felt everyone was against her."

The killings are the latest in a series of high-profile infanticide cases across the country, including those of Andrea Yates, who drowned her five children in the family's Houston bathtub in 2001, and LaShaun Harris, convicted of tossing her three young sons into San Francisco Bay in 2005. Both women stood trial on murder charges but were ultimately declared legally insane - Harris by a judge and Yates by a jury in her retrial.

In other developments, County Executive Tom Suozzi announced a review of the Social Services agency's contacts with the family to determine whether anything could have been done to prevent the tragedy. Calls to the agency were referred to Suozzi's office, which said the investigation could take several weeks.

"Obviously something went seriously wrong, and we need to determine whether part of that wrong was with the system itself," Suozzi said.

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