AP Photo/DuPage County Sheriff's Department

Elzbieta Plackowska in a booking photo provided by the DuPage County Sheriff's Department in Wheaton, Ill.

A Naperville, Ill., woman who allegedly stabbed her son 100 times and a girl 50 times told police there were "devils" inside the children that she needed to kill, according to a prosecutor.

At 40-year-old Elzbieta Plackowska's bond hearing Thursday morning, DuPage County State Attorney Robert Berlin explained Plackowska's alleged comments. "She stated the children had evil inside of them and she was trying to drive the devil out of them," Berlin said, according to NBCChicago.com.

Police say that on Tuesday Plackowska fatally stabbed her 7-year-old son Justin 100 times and 5-year-old Olivia Dworakowski 50 times, according to the Chicago Tribune. At the time, Plackowska was babysitting her son and the girl at Olivia’s home in Naperville, about 30 miles west of Chicago, the newspaper reported. She allegedly told the kids to kneel and pray before stabbing them, NBCChicago.com reported, and also told her son that he was going to heaven.

Prosecutors say both the kids' throats were slashed, the Tribune reported.

Watch US News crime videos on NBCNews.com

After the murders, Plackowska tried to go to a Naperville church but found it closed, so she left a message on its answering machine saying she had done something bad and needed assistance, Berlin said, according to The Associated Press. Covered in blood and with scratches on her hands, she went to a friend's home where her other, adult son was staying and told them that she had been robbed, Berlin said.

Prosecutors say Plackowska initially told police a stalker broke into the townhouse and committed the crimes, the Tribune reported.

Plackowska later told police that she stabbed her son to death to hurt her husband who "didn't appreciate her," according to NBCChicago.com. She said she killed the girl and two dogs because they witnessed the crime, NBCChicago.com reported.

Berlin said investigators found two blood-stained knives; one in the kitchen sink at the townhome and another in Plackowska's car, according to the AP.

Stay informed with the latest headlines; sign up for our newsletter

"In all my years in law enforcement, this is the most gruesome and horrific crime scene that I have seen," Naperville police Chief Bob Marshall said at the news conference, according to the AP.

Plackowska is being held without bond on two counts of first degree murder, NBCChicago.com reported. Berlin said Plackowska has no prior history of violence, the AP reported.

The Associated Press contributed to this story.

• Former Penn State president faces charges linked to Sandusky sex case
• NBC/WSJ/Marist polls: Obama leads in Iowa, running neck and neck in NH, Wis.
• 'Pure mayhem' as New York City tires to get back to work
• Campaign ad spending closes in on $1 billion
• Cops: At least 3 shot during Hollywood Halloween celebrations
• Diesel spill pollutes waters between Staten Island, NJ
• 2 children stabbed to death in Ill. home; victim's mom in custody

Updated at 5:27 p.m. ET: Two children were found stabbed to death inside a Naperville, Ill., home, and the mother of one of them was taken into custody for questioning, authorities said.

Naperville police responding to a request for a welfare check on Tuesday night found the bodies of a boy and girl in a townhome. The children were believed to be her 8-year-old son and a 5-year-old girl she had been baby-sitting, law-enforcement sources said, according to the Chicago Tribune.

Two dogs were also found dead inside the home, a source told the Naperville Sun.

“There is no reason to believe any additional subjects are at large at this time,” police said in a statement issued Wednesday morning.

A law-enforcement official told the Chicago Tribune the woman had been distraught for several days after the death of her father. 

More content from NBCNews.com:

• Blaze devastates NY community built by firefighters
• Tree toppled by Sandy exposes skeletal remains
• Romney training manual for poll watchers causes stir
• Sandy leaves NYC subway system licking its wounds
• Colorado teen charged as adult in killing of Jessica Ridgeway, 10

Follow US news from NBCNews.com on Twitter and Facebook

File this under "Excuses Traffic Cops Don't Hear Every Day."

A Chicago-area man who allegedly was clocked driving 111 mph through a 45 mph forest preserve told a patrol officer he was in a hurry to “try to go have sex with a girl he liked.”

Zachary P. Ramirez, 21, of Naperville, which lies about 20 miles west of downtown Chicago, was caught speeding through Springbrook Prairie Forest Preserve last Saturday, according to the Chicago Sun-Times.

Police Sgt. Gregg Bell told the paper an officer saw Ramirez's 1994 Honda Prelude run a red light, then run a stop sign. Another officer pulled him over and asked him why he was traveling so fast.

For sex, he said.

Naperville Police Department via NBC Chicago

Zachary P. Ramirez is accused of driving 111 mph in a 45 mph zone.

The officer’s radar unit initially clocked the car traveling at 104 mph “and finally locked at 111 (mph),” Bell told the Sun-Times.

Disobeyed light and stop sign
Police also allegedly found 0.2 grams of marijuana in the car. Ramirez faces charges of speeding 40 mph or more over the limit, according to the paper. He also was charged with drug possession, disobeying a traffic light and disobeying a stop sign.

Ramirez is free on $200 bond, the Sun-Times reported. His arraignment date is pending.

See the story at NBCChicago.com.