An 18-year-old Largo man is accused of beating his 3-month-old baby son.

Robert Russell Barnes was arrested Thursday night and charged with aggravated child abuse.

Barnes told police the baby, named Anthony, fell from a swing or was dropped on a TV stand.

Barnes' mother, Stacy Tuttle, said her son had told her the same thing.

"He said, 'Mom, I had the baby in the swing,'" she said. "He says, 'And the next thing I knew, the baby fell out of the swing and hit the floor or hit the arm that the swing is connected to.'"

But doctors found fingerprints on the baby's head that suggest the child was beaten, police said. The baby had bruises on its face, bleeding behind the eye and may have suffered a concussion.

Tuttle said Barnes went to the hospital with the baby, and that she's certain a beating did not take place.  She said Barnes loves his son.

"My son, on record, he would die for that child," she said. "He loves that child to death. He's around his nieces and nephews every day. He wouldn't harm that child."

Barnes' sister, Angela, said she thinks her brother is getting the raw end of the deal.

"I know my brother is never like that," she said. "I see him with Anthony all the time. He loves him, he cuddles with him, he takes him everywhere."

Barnes also was charged with carrying a concealed electric weapon and driving without a valid driver's license. He is being held in the Pinellas County Jail.

According to the Tampa Bay Times, Barnes' record includes seven arrests in Florida, including a guilty plea last year for aggravated battery with a deadly weapon.