Two young children were stabbed to death with the mother of one of them being held without bond.
Investigators say the children begged for their lives.
Elzbieta Plackowska gave police a taped confession and also told them that she believed that she was not appreciated for being a fine wife and fine mother.
At the scene of the murders, there is a growing tribute to the children with candles, stuffed animals and flowers.
Inside the home, authorities are calling this a scene of unimaginable horror.
Plackowska was so unhappy with her marriage, prosecutors say she killed her 7-year-old son, Justin, to hurt her husband.
"She stated she was angry with her husband because he was gone most days as an over-the-road trucker, said DuPage County States Attorney Bob Berlin. "And she also had to work as a cleaning lady and she felt that was beneath her."
Tuesday night, prosecutors say Plackowska was babysitting 5-year-old Olivia Dworakowski at the girl's home on Quin Court while the child's mother worked.
They say Plackowska told Justin and Olivia to go to bed, but the kids were jumping on the bed in the master bedroom.
That's when Plackowska, authorities say, grabbed a knife.
"She began stabbing her son, Justin, and told him he was going to heaven tonight," Berlin said. "He pleaded for his life and told her to stop, but she continued stabbing him until he was dead."
Prosecutors say she then killed Olivia because she was a witness.
"In all my years in law enforcement, this is the most gruesome and horrific crime scene that I have seen," said Naperville Police Chief Bob Marshall.
Authorities say Plackowska called her church, and left a message she had "done something bad."
Then she went to a friend's home, claiming she had been robbed. Someone there called police to report the robbery, which police later determined was a lie.
"We're all collectively blown away," said neighbor Al Karman. "Nobody can wrap their heads around what happened here."
About the same time, Olivia's mother called police, asking for help finding her daughter.
"The senseless taking of the lives of these two children defies logic," Marshall said.
Plackowska is from Poland and came to the United States on a vacation visa 12 years ago. Her immigration status is under investigation.
She is being held without bond and will be back in court in three weeks.