(CHICAGO) -- The Illinois woman charged with the murder of her 7-year-old son, who she stabbed over 100 times, and a 5-year-old girl in her care was denied bail by a Chicago-area court on Thursday.
Elzbieta Plackowska, of Naperville, Ill., will be held without bond in DuPage County, ABC News' Chicago affiliate WLS-TV reported. The 40-year-old woman was charged with two counts of first-degree murder Wednesday evening.
Plackowska, who was babysitting the 5-year-old girl, was arrested after the children were found by police slashed and stabbed on Tuesday at 10:15 p.m.
The children were identified as her son, Justin Plackowski, and Olivia Dworakowski.
Plackowska was covered in blood when she was taken into custody, according to WLS-TV. Investigators from the Naperville Police Department and the DuPage County States Attorney's Office questioned her before charges were filed.
Police found two dead dogs in the home that also were stabbed, WLS-TV reported. Investigators said there was no reason to believe that any additional suspects were at large.
The Chicago Tribune reported that Plackowska has given authorities various explanations for what happened, including hearing demonic voices that led her to kill the children.
The girl attended kindergarten at Brookdale Elementary School and the boy was a student at Scott Elementary School.
"This is an extremely difficult time, but this is an extremely strong community and I'm confident in this community and our school district that we will pull together and move through this tragic event," said Naperville School district Superintendent Dan Bridges.
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