An Ohio woman has been indicted for murder for allegedly causing the death of her 4-year-old stepson in March by placing him in scalding water as punishment, prosecutors announced Monday.

At a Monday press conference, Warren County Prosecutor David Fornshell said Anna Ritchie, 25, placed 4-year-old Austin Cooper in the hot water because the boy did not want to take a bath.

Get push notifications with news, features and more.

“To teach him a lesson as a form of punishment, she decided to run scalding water in the bathtub,” Fornshell said.

Fornshell estimated the water was 134 degrees, and that Ritchie allegedly placed him in there for 20 to 25 minutes. When she took Austin out of the tub, “his skin was falling off his legs, he was bleeding significantly,” Fornshell said.

“When you’re looking at temperatures at that level, you’re talking about a scalding injury occurring somewhere between one and four seconds,” he said. “Just to be in that tub for a period of a minute or two would have to be the most excruciating pain that you could go through.”

Subsequently, Fornshell said Ritchie allegedly put Cooper in pajamas and socks and put him to bed. He said nobody checked in on Austin from 4:30 p.m. until 9:30 a.m. the next day, when his father allegedly discovered him dead.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Fornshell said that Ritchie and her husband had recently become Austin’s primary caregivers and that Ritchie took care him while her husband was at work.

“It’s our belief that she resented becoming the primary caregiver of this child,” Fornshell said.

The indictment includes charges of murder, involuntary manslaughter, felonious assault and endangering children, Fornshell said. She faces 15 years to life if convicted.

Ritchie’s lawyer, Seth Cantwell, tells PEOPLE that Ritchie’s arraignment is tomorrow and she will plead not guilty. He had no further comment about the specifics of the case.