Police arrested a man and woman on charges of culpable negligence and child neglect after a 3-year-old boy was injured when he fired a loaded gun he found under the mattress in their Arlington apartment.

Barbara Powell, 22, and Gregory Chisholm, 24, were arrested Monday evening, eight hours after the boy was hospitalized with a shoulder wound caused either from the bullet or piece of concrete that ricocheted off the floor after the gun was fired.

The boy was taken to a hospital for stitches, but his injuries were not life-threatening. His 5-year-old sister was in the room when the gun went off, but she was not hurt.

The relationship of the adults to the children was redacted from the police report.

According to the arrest report, Powell and Chisholm said they were lying in bed when they heard a loud pop and saw the boy injured.

Police said Powell initially told them the gun was hers and she had placed it under the bed. She later told officers the gun belonged to Chisholm.

The report says Chisholm admitted to owning the gun and placing it under the mattress the night before.

The 5-year-old told the Florida Department of Children and Families' child protection team, "My daddy always keeps the gun underneath the mattress."

"It’s just so scary," said DCF spokesman John Harrell. "We would think that parents would know that it only takes a few moments for something to happen."

A criminal attorney said it's going to be tough for these adults to defend their actions in court because their was no reasonable attempt to keep the gun secure.

"It would be difficult to have a defense in this case, if the facts as stated are true," said attorney Jonathan Zisser. "That there was a loaded firearm placed under a mattress and the parents knew that it was there, and also knew that the child was in the home. I think that is pretty textbook in terms of criminally negligent behavior."

In an effort to prevent these kinds of incidents, the Jacksonville Sheriff's Office encourages the use of gun locks.  The JSO will even provide gun locks to the public for free and currently has 200 available.  Call 904-630-0500 for more information.