POST FALLS - A 25-year-old female baby sitter was charged with first-degree murder on Friday after a 3-year-old boy she watched died from head injuries from being shoved to the floor.

Cohen Johnson, of Post Falls, died at Sacred Heart Medical Center on Friday after suffering a fractured skull during Monday's incident.

Amanda Leann Skogen, also of Post Falls, a friend of the family's who confessed to injuring Cohen, was then arrested without incident and booked into the Kootenai County jail.

Police say Skogen became angry when Cohen urinated on himself and her and shoved the boy on a carpeted floor with a concrete foundation.

"It appeared to be a split-second that changed a lot of lives forever," Post Falls police Capt. Greg McLean said. "There was no indication that this was going to happen."

Skogen does not have a criminal history and police believe she doesn't have a history of losing her temper while baby sitting.

"In her confession, she said she acted out of frustration," police Chief Scot Haug said.

"The child's injuries are consistent with what she described. He was pushed from the front and he hit the back of his head."

Haug said it is his understanding that Cohen was taken off life support on Friday.

The only other person at the home in the 500 block of North Elm Road was Cohen's 2-year-old sister.

Skogen has baby sat the siblings off and on for several months, police said, adding that she was paid for the service.

Haug said he doesn't believe Cohen's parents have had contact with Skogen since the incident, per police officers' advice during the investigation.

When a child under 12 dies as a result of injuries from a battery, the act does not have to be pre-meditated to draw a first-degree murder charge.

"The county prosecutor and us are in agreement with this specific charge," McLean said.

Cohen's parents do not wish to speak to the media, police said.

Police said Skogen has cooperated with investigators during the investigation. She showed remorse over the incident.

When Skogen called police on Monday, she said Cohen was breathing but unresponsive.

When officers arrived, they were told by Skogen that she was attempting to remove urine-soaked clothes from the boy when he became "limp" and unresponsive. He was transported to Kootenai Medical Center.

Initially, police believed Cohen might have ingested something that caused him to slip into an unresponsive state.

However, a CT scan revealed that the child had a bleeding skull fracture and medical personnel believed the injury was suspicious.

Cohen was flown to Sacred Heart, where he underwent emergency surgery.

Detectives responded and, as a result of the investigation, Skogen admitted to shoving Cohen.

A medical examiner's report and autopsy will be completed.

Police say it's the first murder charge in Post Falls in about 10 years.