TAMPA — A 4-year-old Tampa boy under the watch of his mother's boyfriend suffered a gunshot wound to the chest Tuesday morning, according to the Hillsborough County Sheriff's Office.

In a news conference, Col. Donna Lusczynski called the shooting an accident and said detectives are investigating how the child could have gotten his hands on the gun, but she stopped short of saying the wound was self-inflicted.

"This is obviously a horrible accident and we're still trying to determine what caused it," Lusczynski said.

Investigators were interviewing family and neighbors about what happened and how the gun was typically stored in the home, located in the 12000 block of Tinsley Circle at Key Vista Apartments near University Mall.

Deputies charged the boyfriend, 26-year-old Akia Thomas, with being a felon in possession of a firearm.

Thomas has a lengthy arrest record, which includes convictions for cocaine and marijuana possession, according to Florida Department of Law Enforcement records. He spent seven months in state prison in 2011 for possessing more than 20 grams of marijuana, records show.

"He shouldn't have (a gun) around him or be around them," Lusczynski said.

The boy, Roshad Richardson, was taken to St. Joseph's Hospital and was doing well after surgery Tuesday afternoon, said his mother, Delicia Forte.

"The family is good," said Forte, 24. "I have a strong backbone and I'm just grateful my son is doing great. He's talking, he's alive, he's stable, he's everything."

Forte declined to speculate about how Roshad was injured. She was taking her 1-year-old daughter to day care at the time of the shooting, about 8:30 a.m. Her 6-year-old daughter, who also lives in the apartment, was at school at the time, leaving Thomas alone with the boy.

"The only thing I want to discuss is my healthy, stable son," Roshad told a Tampa Bay Times reporter. "He'll be coming home soon."

Times news researcher John Martin contributed to this report. Contact Anastasia Dawson at adawson@tampabay.com or (813) 226-3377. Follow @adawsonwrites.