An Inverness woman was arrested after deputies said she beat her six-month-old son so badly that he died.

Brittany N. Arnett, 20, is facing murder charges in connection with the death of her son, Hadley.

According to the Citrus County Sheriff's Office, Arnett and her boyfriend brought the baby to Citrus Memorial Hospital the morning of Jan. 28. At the time, the baby was not responsive or breathing. Medical staff tried to revive the baby but to no avail, the report said.

Investigators said the baby was bruised on the left side of his rib cage and had what appeared to be a bite mark on the left thigh.

An autopsy was conducted the following day, during which time the medical examiner found the baby had suffered several injuries that led to his death, investigators said.

The report said the baby had brain hemorrhaging, a separated spine, broken ribs and lacerations in his mouth, among other injuries.

Investigators said they learned that on Jan. 27, Arnett was left alone with the baby throughout the day, and that when her boyfriend returned home, the baby had difficulty focusing and was sensitive to touch. Investigators said the baby also had blood in his mouth, which had to be removed by a suction ball.

On Monday, detectives said Arnett admitted to causing the injuries that led to the baby's death. They said she told them that she became frustrated and angry that she was left alone with him, and that around noon, she put the baby in his swing.

Investigators said Arnett told them that over the course of the next couple of hours, she admitted to slamming the baby's face into the tray of the swing and grabbing the baby around the rib cage and yanking him from the swing with such force that the back of his head hit the swing.

Arnett said she knew the baby was hurt, but she was afraid to tell her boyfriend or seek medical attention for fear of getting into trouble, the report said.

The report said Arnett then told detectives that she put the baby to bed at 10 p.m. that night, and the last time she heard the baby breathing was at 5:30 a.m. on Monday.

Neighbors say they never saw Arnett or the baby and never noticed any trouble.

"It was always pretty quiet like I said other than the dogs that tended to wander up and down the street,” said Dayna Peterson, a neighbor. “You never really saw anybody coming in or out of here."

“It’s very sad, I mean, I have a 5-year-old daughter and anything like that it touches me in the heart and everything,” said Eric Connor, a neighbor.

Arnett was arrested and charged with first-degree murder. She has been booked into the Citrus County Detention Facility.

A memorial service was held for Hadley Monday night. Family members declined to comment.