A woman and 4-year-old boy believed to be her son were found dead in a Joliet home Sunday morning.

Joliet police said they have in custody a man believed to be the shooter of the two victims.

No names were released as of late Sunday afternoon.

The shooting happened at a house in the 700 block of Garnsey Avenue.

Police Chief William Evans described the suspect as a part-time resident of the house.

“It does appear that there was some sort of domestic relationship,” Evans said at a news conference. “To what extent, we don’t know.”

The 29-year-old suspect has not been identified. He has not been charged, noted police spokesman Sgt. Dwayne English.

He was found at the residence with an apparent gunshot wound to the ankle that police believe to have been self-inflicted.

“Officers also discovered a 36-year-old female and a 4-year-old male unresponsive outside in the backyard of the residence with apparent gunshot wounds,” stated a police news release on the shooting.

“Both individuals were pronounced deceased at the scene,” Evans said.

[ PHOTOS: Police investigate shooting deaths of woman, child in Joliet ]

The suspect was taken to Silver Cross Hospital in New Lenox and later was transferred to Loyola Medical Center in Maywood under police guard, police said. His injury was considered non-life threatening.

Evans said police received a number of 911 calls at about 6:55 a.m. regarding gunshots in the area.

“Callers also reported seeing a shirtless male discard a firearm running near nearby train tracks,” the police new release said.

Another 8-year-old boy that police described as having special needs was found uninjured in a bedroom at the house. He was taken to Saint Joseph Medical Center in Joliet.

The woman killed in the shooting is believed to be the mother of both boys, police said.

A gun and spent shell casings that appeared to match the gun were found at the scene of the shooting, police said.

“Anyone with video footage or information related to this shooting is encouraged to contact the Joliet Police Department Investigation Division at 815-724-3020,” stated a news release from the police department. “They can also contact Will County Crime Stoppers at 800-323-6734 or online at online at https://crimestoppersofwillcounty.org/ if they wish to remain anonymous. ”