A Gainesville man has been charged in an assault on his 3-year-old stepson that left the boy in critical condition.

Alejandro Chavez, 24, was charged early Friday in the Thursday afternoon assault at a home in the 2900 block of Dorsey Peek Road, Hall County Sheriff’s Maj. Jeff Strickland said.

Chavez was alone with the boy and an infant son while the boy’s mother was at work, Strickland said. When the mother returned home shortly after 5 p.m. Thursday, she found the boy had abdominal injuries and two black eyes and called 911.

Sheriff’s deputies and paramedics arrived at the house and Chavez was brought in for questioning, Strickland said. He was booked into the Hall County jail on felony charges of aggravated battery and cruelty to children shortly after midnight.

The boy, who is not being named because of his age, was airlifted by helicopter to Children’s Healthcare of Atlanta at Scottish Rite, where he underwent surgery. He remains in critical but stable condition in the hospital’s intensive care unit, Strickland said.

"The child was severely injured," Strickland said.

Chavez, a machine operator who worked in Jefferson, was in the country illegally, Strickland said.

Chavez and the mother of the boy have an infant son together. The baby was placed in the temporary protective care of the Hall County office of the state Department of Family and Children Services, Strickland said.

Strickland said investigators do not know what prompted the attack on the boy.

Chavez remains in the Hall County jail without bond.