Authorities have upgraded the charges against a Fairfield mother who has been jailed since December in connection with the death of her infant son.

The aggravated child abuse charge against 31-year-old Ratunda Smith was dismissed last week and a new charge of murder filed, court records show. D'Mario Hall, who was 2 months and 24 days old, died at Children's of Alabama after police say he was injured during an argument between his parents.

Smith remains in the county jail with bond set at $60,000. At her initial court appearance, a judge ruled that should Smith make bond, she must remain at home on 24-hour-a-day electronic monitoring.

D'Mario Hall was injured about 10 a.m. on Dec. 4, 2017 at the Mattie Gill Jackson Gardens public housing community. Police and medics were called to the apartment after a domestic dispute erupted there, said Fairfield Police Chief Nick Dyer.

When they arrived on the scene, they found D'Mario unresponsive. He was rushed to Children's of Alabama where he was pronounced dead at 2:15 p.m. on Dec. 7.

Authorities said the boy's father was holding the baby when Smith fought him and caused him to drop the baby onto the concrete floor. She then picked up D'Mario by his clothing and shook him and swung him, according to an affidavit in the case.

D'Mario suffered a fractured skull, bleeding on the brain and retinal damage.

Smith's four other children - two boys and two girls ages 7 and under - were at the hospital with the family and were taken into protective custody by Birmingham police. Initially they were placed into the custody of DHR. The father has not been charged with any crime. Dyer said both parents are deaf and an interpreter has been used to help with the investigation.

A court date has not yet been set for Smith.