Updated 11/02/12 – 2:13 p.m.

CHICAGO (CBS) – The woman accused of killing her 7-year-old son and the 5-year-old girl she was babysitting allegedly went to confession at a Naperville church before the murders.

CBS 2’s Susanna Song reports, according to DuPage County prosecutors, Elzbieta Plackowska visited St. Elizabeth Seton Church with her son, Justin Plackowski, and 5-year-old Olivia Dworakowski on Tuesday, just hours before she stabbed them to death.

According to prosecutors, Plackowska visited the confessional, although it is not known which priest she spoke to , or what she told him. Anything she did confess would be considered privileged communication, meaning it would be inadmissible in court.

Authorities said Plackowska went back to the church after killing the two children, but the doors were locked.

Justin Plackowski and Olivia Dworakowski (Naperville Community Unit School District 203/Facebook)

Plackowska and her husband were parishioners at the church. Those at the church on Friday declined to answer questions about Plackowska’s visit on Tuesday.

Meantime, a new judge has been assigned to the case. The DuPage County State’s Attorney’s office said Judge Robert Kleeman has been assigned to the case, after Judge John Kinsella handled Plackowska’s bond hearing.

According to the Daily Herald, Plackowska’s public defender was allowed the option of striking two judges from consideration for the case, and asked that the case not be assigned to Kinsella or Judge George Bakalis, who presided over the trial of Marilyn Lemak, who killed her three kids in Naperville in 1999. Lemak pleaded not guilty due to insanity, but was convicted and sentenced to life in prison.

Plackowska, 40, was charged with two counts of first-degree murder late Wednesday night. She was ordered held without bail Thursday morning and is on suicide watch at the DuPage County Jail.

DuPage County State’s Attorney Bob Berlin called the bedroom where she allegedly killed the two children “a scene of unimaginable horror.”

Authorities Justin and Olivia were jumping on the bed in the master bedroom Tuesday night, when Plackowska allegedly told them to get down, kneel on the floor, and start praying.

“She began stabbing her son, Justin, and told him he was going to heaven tonight. He pleaded for his life and told her to stop,” Berlin said. “But she continued stabbing him until he was dead. She then turned her attention to 5-year-old Olivia, and began stabbing her with the knife multiple times. She, as well, pleaded for her life.”

Prosecutors said Plackowska admitted killing Justin because she wanted to hurt her husband, who she believed did not appreciate her. She also allegedly admitted killing Olivia, because she witnessed Justin’s murder.

Berlin said Plackowska made that admission only after changing her story several times. Plackowska first claimed the children were killed by a robber while she was outside smoking. Then she said the kids were killed by someone who had been stalking her. Then she claimed she was battling the devil, and was trying to save the children from evil.

According to Berlin, Plackowska finally admitted those claims were lies, and she killed her son because she was angry with her husband for regularly leaving her at home alone with Justin while he worked as a trucker.

Berlin also said Plackowska claimed her husband didn’t treat her the way she deserved, and didn’t appreciate how good of a wife she was.

Plackowska’s husband, Artur Plackowski, told the Associated Press he has no idea why his wife killed Justin and Olivia. He said she had told him she loved him the day before the murders, and he denied the two were having problems.

Counselors have been at the schools the two children attended to help students and teachers in the aftermath of the murders. Naperville police officers, paramedics and others who responded to the murders are also undergoing mandatory counseling after viewing the bloody murder scene.

Mourners continued continue to lay fresh flowers and dolls for the two children Friday morning outside the home where they were slain.

Several hundred people attended a candlelight vigil Friday night in Naperville for the two children murdered in the western suburb.

Even Naperville’s relentlessly upbeat Mayor, George Pradel, was reduced to tears as he urged everyone to go home and tell husbands and wives, sons and daughters, and brothers and sisters that they are loved.