-- A 45-year-old U.S. Marshal was shot and killed Thursday morning as he and other officers were ambushed by gunfire while trying to serve a warrant to a woman in Pennsylvania's capital.
After entering the residence on the 1800 block of Mulberry Street, task force officers placed Pierce in handcuffs and noticed several children on the second floor, said David Freed, the U.S. Attorney for the Middle District of Pennsylvania.
"At that point, the officers heard gunfire that appeared to emanate from the second floor of the residence," Freed said.
A man, later identified by the U.S. Department of Justice as Kevin Sturgis, 31, of Philadelphia, had opened fire on the officers.
Hill and officer Kyle Pitts, a 10-year veteran of the York City Police Department, were struck by bullets, Freed said. Other task force members quickly removed the wounded officers out the back of the house and set up a perimeter.
"Preliminary indications from the investigation indicate that a male individual then exited the front of residence firing at law enforcement officers," Freed said. "Gunfire was returned and that male was killed in front of the residence."
Sturgis was pronounced dead at the scene.
Hill and Pitts were taken to a hospital, where Hill died and Pitts was undergoing surgery for non-life-threatening injuries.
"None of us has sufficient words to express our grief and sorrow," Freed said. "The Hills have lost a father, a son, a brother far too soon. Our community has lost a hero, who was doing nothing more than his duty."
Sturgis had two active warrants for his arrest, including one for failure to appear for sentencing for illegal possession of a firearm, the Department of Justice said in a press release. Sturgis also had a juvenile adjudication, the same as a conviction in adult court, for rape.
Hill was highly involved in the 2014 manhunt for Eric Matthew Frein, the domestic terrorist and murderer sentenced to death for an attack on a Pennsylvania State Police barracks that killed a state trooper. Hill led a large group of U.S. Marshals, FBI agents and state troopers in pursuit of Frein through the Pennsylvania woods.
Hill served in Afghanistan from 1993 to 1996. As a U.S. Marshal, Hill returned to help the country set up a judicial system and received the U.S. Marshals service distinguished group award for his "significant contributions in Afghanistan." Hill also was a trained explosives breacher and a firearms and tactical training officer, Pane said.
"Deputy Hill made the ultimate sacrifice," said Pane, holding back tears. "Deputy Hill served the American people and the citizens of this community with courage. He will be missed and words cannot say how much."
Dauphin County District Attorney Fran Chardo said his office is in charge of investigating the officer-involved shooting, in keeping with county protocol.
"Based on the fact that the dead suspect opened fire first, it appears, preliminarily," Chardo said, "that it was a justified used of deadly force."
Pierce was arrested and is being held on $200,000 bail.
ABC News' Gregory Croft, Jack Date, Morgan Winsor and Mark Osborne contributed to this report.