The two officers were wounded, but are expected to survive, Jasper County Sherriff Chris Malphrus said Friday.
"We're not clear on why this happened - what his intent was," Malphrus said at a news conference.
Jasper County deputy Justin Smith and Hardeeville police Sgt. Kelvin Grant rushed to the home around 6 p.m. Thursday after a 911 caller said Jose Trejo was shooting at a woman, Malphrus said.
Trejo, 26, was killed in the ensuing gunbattle with police. Smith was shot in the shoulder and hand and will have surgery Friday. Hardeeville police Sgt. Kelvin Grant was wounded in the armpit and may need surgery, Malphrus said.
Both men remain in a hospital in Savannah, Georgia.
Trejo was known to police, facing domestic violence and drug charges in the past, the sheriff said.
This was the third shooting involving an officer in Hardeeville, a town of 4,200 about 15 miles north of Savannah, in the past three years. Jasper County deputies have been involved in two police shootings in the county of 27,000 people this year.
There is body camera footage of the shooting, but the State Law Enforcement Division has not released it. The agency investigates most police shootings in South Carolina.
Trejo is Hispanic, Smith is white and Grant is black, agency spokesman Thom Berry said.
Hardeeville Police Chief Sam Woodward said the officers had to go into the home and not wait for backup because they were told someone was shooting a gun and had no idea how many people were at risk.
"If we think somebody is hurt or injured inside the house, we're going to enter it," Woodward said. "We can't wait on SWAT."
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.