JACKSONVILLE, Fla. -- Adrian Smith listened in court Wednesday as prosecutors painted him as a murderer who lost his temper and shoved a baby wipe down a baby's throat to suffocate him.

Smith claims the death of a 4-month-old boy that he called his son an accident. The child was rushed to Wolfson Children's Hospital in February 2006. Doctors found a baby wipe lodged in his throat.

The state's final witness, Dr. Bruce McIntosh, testified that Adrian Smith Jr. had a injury to his lip consistent with someone forcing a rag into his mouth.

The defense asked if anything else could have cased such a cut, such as giving a presciption medication to a child who is resisting.

"In 38 years of pediatrics prescribing amoxicillin probably thousands of times, I've never had a child suffer a lacerated (lip) from being given an antibiotic," McIntosh said. "I've never personally seen that."

After the state rested, the defense called the child's mother to the stand and asked her if the boy could have accidentally gotten the wipe in his throat.

"Besides changing diapers, were the wipes ever used for anything else?" asked defense attorney Pat McGinnis.

"Yeah, (he'd) wipe his face and wipe his hands, and sometimes used it for a bib like a napkin," Donneka Steadman said.

The state said there was no way the child could physically have put the wipe down his throat and cross examined the mother:

Prosecutor: "You never saw your son, Adrian Smith Jr., put a baby wipe to his mouth?
Steadman: No I had not.
Prosecutor: You never saw him put anything like a paper object or a cloth object to his mouth, did you?
Steadman: No, I haven't.

Leaving court on Wednesday, Steadman talked about the pain of losing her baby.

"I wish I had him back, but I know it's not going to happen," Steadman told Channel 4's Dan Leveton. "I feel like I wish I never would have left my son unattended. I wish I could have did something different, but I know I can't."

Smith, 36, is charged with second-degree murder. He has been held without bond since his arrest.

The defense will continue to present its cast on Thursday, with closing arguments expected by the end of the day.