UPDATED: 10/31/2012 – 10:08 p.m.

CHICAGO (CBS) — Police in Naperville have charged Elzbieta Plackowska in the stabbing deaths of two small children at a suburban town home overnight.

Plackowska, 40, of the 200 block of Bailey Road, is expected to appear in bond court Thursday morning at 8 a.m.

Naperville police on Wednesday had questioned Plackowska who had been behaving erratically just before the two stabbing deaths of her 7-year-old son and a 5-year-old girl she had been babysitting at the girl’s Naperville townhome, law enforcement sources said.

The babysitter had been arguing with her husband after her father had recently died in Poland, and she wanted to return there, against her husband’s wishes.

Other sources also noted that the woman contended she feared that demons were threatening the children.

The babysitter took the children to a church before they were slain, then the woman tried to visit the church again after the killings.

The mother of the slain girl whom the babysitter was looking after, Marta Dworakowski, a nurse, declined to comment when reached by phone Wednesday. Her daughter, Olivia, attended Brookdale Elementary School.

Officials planned to release details of the case after the suspect’s court appearance.

CBS 2’s Susanna Song reports two young children, were found stabbed to death during a well-being check by police around 10:18 p.m. Tuesday, at a four-unit town home building at 888 Quin Court in Naperville. The children are not related.

LISTEN: WBBM Newsradio’s Mike Krauser Reports

WBBM Newsradio’s Mike Krauser reports the woman who is being questioned was babysitting another woman’s child while the other mom was at work. It was that mother who presumably called police.

Two dogs were also found killed inside the home.

CBS 2’s Suzanne Le Mignot reports the babysitter was not at the townhome when the bodies were found, but the Daily Herald repots police later found her about an hour later, and she was covered in blood.

CBS 2’s Vince Gerasole reports Naperville Police Chief Bob Marshall confirmed three separate locations are involved in the investigation.

CBS 2’s Jim Williams reports authorities removed the victims’ bodies from the home Wednesday afternoon; a yellow tarp concealed the sad work.

A woman who lives inside the building right next door to where the murders happened said, “I know nothing.”

“This is terrible, it’s terrible,” she said.

Police have been in and out of the townhouse all morning, collecting evidence.

Neighbors said the news was devastating.

“Why do they have to do where the kids are involved? They’re the victims,” neighbor Nina Trimble said. “It’s just heartbreaking to think something goes on. You hear so much of it, but you just don’t … aren’t in the middle of it.”

Fellow neighbor Gina Blach said police haven’t said anything to her about the case, and she hasn’t asked.

Neighbors emphasized how quiet the area is. There aren’t many children who live along that cul de sac.

One of the children who was killed was a student at to Brookdale Elementary School. The other child attended Scott Elementary school.

Two different school districts were impacted by the murders. Each district was trying its best to cope on Wednesday.

As children left a Halloween costume assembly at Scott Elementary School, where the 7-year-old boy was a student, parents struggled to understand the violent death of a classmate.

“It’s just a tragedy when you hear something of that brutal nature happening in your area, and it’s very scary to think about, really,” Roslyn Gonzalez said. “I have a 7-year-old myself, and to think something happened like that to our school, children that our kids see every day, it’s very tragic.”

Naperville Community Unit School District 203 Supt. Dan Bridges said, “The loss of a child at any time is a tragic and upsetting event, and not only just for a school, or one school district, but for an entire community.”

Scott Elementary parent Lorenzo Gonzalez said he hopes the victims’ families “take it day by day.”

Counselors have been at both schools to help both the students and teachers in the aftermath of this tragedy.

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