A Naperville, Illinois, woman was found guilty Monday of fatally stabbing her 7-year-old son and a 5-year-old girl she was babysitting.

In a closed bench trial, Elzbieta Plackowska, 45, was convicted of ten counts of first-degree murder and two counts of aggravated cruelty to animals in connection with the 2012 stabbing deaths. A judge rejected the defense’s claim that Plackowska was insane when she committed the murders, according to WLS.

“She loved them. There is no way she could do this to them if she knew what she was doing,” defense attorney Kristen Nedval argued in court.

However, DuPage County Judge Robert Miller believed that Plackowska knew what she was doing when she stabbed her son, Justin Plackowski, 173 times and Olivia Dworakowski, the girl she was babysitting, 94 times, the Daily Herald reported.

Elzbieta killed her son and Dworakowski at the girl’s home on October 30, 2012, while her mother worked a night shift at a dialysis lab. Officers found Justin and Dworakowski’s bodies in the master bedroom next to two dogs that she also fatally stabbed. The 45-year-old also slashed the two kids’ throats sometime during the relentless assault, according to the Chicago Tribune.

“It seems evident to the court that it was mental illness that brought the defendant to the crossroads of having to make such a choice,” Judge Miller said. “Despite the sad circumstances, mental illness alone is only one of the two linchpins in the definition of insanity.”

The Naperville woman admitted to taking the children to church before carrying out the slayings. Authorities said the children were jumping on the bed when Elzbieta instructed them to get on their knees and pray as she stabbed them—all while they begged for their lives.

DuPage County State’s Attorney Bob Berlin noted that the 45-year-old refuted her own insanity plea when she said, “I’m not supposed to, but I have to” shortly after committing the unthinkable murders.

Elzbieta fled the home after the stabbings and went to a residence where her adult son was staying. He called the police, the Tribune reported.

In court, psychiatrist Dr. Alexander Obolsky testified that the defendant was a narcissist with an alcohol problem. Obolsky claimed that she was driven to kill because she felt unappreciated by her children and trucker husband.

The doctor also stated that he doesn’t believe Elzbieta when she said she saw a dark shadow hover over the children that demanded her to kill them. In fact, he suggested that her varying accounts of what happened on the night in question proved that she wasn’t suffering from a mental illness, according to the Tribune.

“She knew what she had done was wrong and she needed an excuse,” Obolsky said.

Elzbieta faces life in prison following Monday’s conviction.

[Featured Image: WGN-TV]