MIDDLETOWN, Del. (AP) — A man suspected of fatally shooting a Delaware state trooper was shot and killed by officers after a 20-hour standoff at his home, state police said Thursday.

The man, who has not been identified, walked out of the home about 9:15 a.m. He had been holed up there since the fatal shooting of the Cpl. Stephen J. Ballard a day earlier. The man was shot after he “engaged officers” and died at the scene, police said in a statement. Authorities planned a news conference Thursday afternoon to release more details.

Ballard, 32, was shot around noon Wednesday just after he approached a vehicle in the parking lot of a Wawa convenience store near Bear.

State police superintendent Col. Nathaniel McQueen said the vehicle had two suspicious people inside. One man got out of the car and shot Ballard several times before running away, McQueen said Wednesday. The other man was arrested at the scene.

“This is a sad day for our state and for the Delaware State Police family,” McQueen said as Gov. John Carney stood at his side.

Police tracked the suspected gunman to his home in a subdivision of two-story houses near Middletown, about 15 miles (25 kilometers) south of where Ballard was shot. The gunman, alone in the house, refused to leave and fired several shots at officers surrounding the home, state police spokesman Master Cpl. Gary Fournier said. No other officers were injured.

“There have been multiple gunshots that have come from the house at police officers,” Fournier said.

Hostage negotiators were on the scene and established contact with the man in an effort to get him to surrender peacefully, Fournier said. But there was no quick resolution as the standoff stretched into the evening.

Shortly after 8 p.m., police used an explosive device to blow the door of the house off its hinges, but officers did not immediately enter the home, Fournier said.

Officers came under fire again about 4 a.m. Thursday, and authorities used explosives to blow off windows, police said. Outside photographs of the house showed splintered and missing doors and windows.

Sarah Adkins, 18, who lives with her parents on the same street where the suspect was barricaded, said that shortly after arriving home early Wednesday afternoon, she started hearing sporadic gunfire that lasted for about an hour and resumed at intervals.

Adkins said the man believed to be the suspect went to school with her brothers and always seemed friendly, smiling and waving at her when she last saw him a couple of weeks ago.

Police used a robo-calling system to tell residents in the area to stay inside and lock their doors.

Ballard had been on the force for more than eight years, according to state police spokesman Sgt. Richard Bratz.

“My heart is with the officer’s family and the officers who have served beside him,” Carney said in a statement.