ALBANY TOWNSHIP, Pa. (CBS) — The Berks County district attorney says a mother hanged her 8-year-old son and 4-year-old daughter with a dog cable in the basement of their Berks County home. District Attorney John Adams says Lisa Snyder has been charged with first-degree murder and other related offenses in the deaths of Conner and Brinley Snyder.

She is also accused of having sex with a dog.

According to court documents, Snyder told police that the children died by suicide and that 8-year-old Conner was being bullied at school. But investigators didn’t find any evidence of bullying.

What they did find were Google searches and Facebook messages that painted a horrifying picture.

Conner and Brinley were found hanging from a dog cable in the basement of their Albany Township home on Sept. 23 after their mother called 911. The young children were in full cardiac arrest when first responders arrived and were resuscitated, however, they died three days later.

The coroner said the children died by hanging and ruled their deaths homicides.

“Lisa Snyder has maintained that these children committed suicide,” Adams said.

Adams says Snyder ordered a dog cable a day before her children were hanged and picked it up from a local Walmart.

“This is a horrific, tragic incident that has received a lot of attention in our community and we are very saddened by this incident that took place in Albany Township,” Adams said.

Authorities say Snyder told police that Conner was being bullied at school and wanted to die, but witnesses say the young boy was not bullied and didn’t complain about it. Police also gathered video from the school bus that brought Conner home.

“The video showed no signs that Conner was in any distress whatsoever. In the video, he appeared to be a happy child,” Adams said.

According to court documents, Snyder told a friend in early September that she “does not care anymore about her kids.”

Forensic examination of Snyder’s five phones and Google account found the following searches: On Sept. 17, “carbon monoxide in a car how long to die”; On Sept. 20, “Almost Got Away With It best episodes”; And on Sept. 22, “hanging yourself.”

Facebook Messenger conversations obtained in the search warrant allegedly showed Snyder talking about a dog performing sex acts on her.

“Those Facebook records indicate photos and conversations regarding sexually explicit messages about the dog performing sexual acts on the defendant,” Adams said.

Adams added that the children were removed from Snyder’s care in 2014 and were returned to her in 2015. Children services had been involved with the Snyder family until November 2015.

Prosecutors have not made a determination yet if they will seek the death penalty against Snyder. She is being held without bail.

CBS3’s Alexandria Hoff contributed to this report.