- Armed with an automatic AR-15 rifle, the suspect began shooting when they arrived.
- He was killed and four other officers were wounded in the shootout.
Four police officers who died in the line of duty in North Carolina are being remembered for their "heroic acts".
The four were shot and killed on Monday while trying to issue an arrest warrant to a 39-year-old man with an extensive criminal history.
Armed with an automatic AR-15 rifle, the suspect began shooting when they arrived. He was killed and four other officers were wounded in the shootout.
A police investigation is ongoing.
At a news conference on Tuesday, Ron Davis, the Director of the US Marshals Service, described their death as a "loss for the entire country."
"As more and more comes out about this incident, not only will you see how brave they were, you will see examples of that courage and bravery." Mr Davis said.
Law enforcement officials in Charlotte, North Carolina identified the four deceased officers as: Samuel Poloche and William "Alden" Elliott, who were both with the state's Department of Adult Corrections, along with Joshua Eyer, an officer with the Charlotte-Mecklenburg Police Department (CMPD), and Thomas Weeks, a deputy officer with the US Marshals Service.
Three of the wounded officers - Christopher Tolley, Michael Giglio and Jack Blowers - were shot and are expected to make a full recovery. The fourth officer, Justin Campbell, suffered from a broken leg and was discharged from hospital.
Investigators are still trying to piece together what unfolded on Monday afternoon, when officers arrived at a home in the east of Charlotte to serve a warrant to the suspect who was wanted for felony possession of a firearm. He has been identified by officials as Terry Clark Hughes Jr.
Police said the suspect began firing at the officers from the second story of the house when they first showed up, prompting them to call for back-up.
The gunfire then continued, striking additional officers.
"Gunshots were coming from multiple locations in the house," said CMPD chief Johnny Jennings, adding that police are not ruling out the possibility that there was another shooter involved.
The shootout continued for more than three hours, and police estimate more than 100 shots were fired. It ended when police stormed the home using armoured vehicles to smash their way in, destroying windows and doorways.
Officers shot and killed the suspect in the front yard after he exited the house with a firearm in hand, police said.
Two women who were inside the home - one is 17 years old - were taken in by police for questioning. Chief Jennings said both have been fully cooperative with the investigation, and police will not be pressing charges against them at this time.
Police are reviewing body-worn camera footage from the officers involved, but there is no indication that any of the officers died in friendly fire, he also said.
The suspect was known to police with an extensive criminal record and had served "a significant amount (of time) in jail" in the past, according to Chief Jennings.
Police recovered a fully automatic AR-15 rifle at the scene, as well as a .40 calibre handgun and several rounds of ammunition for both guns.
Chief Jennings noted that traditional body armour worn by police officers would not have been able to shield against a rifle round.
"The AR-15 is able to suppress rapid gunfire and holds a great deal of ammunition, and this individual was able to unload several rounds towards our officers within a matter of seconds," he told reporters.
Law enforcement, as well as state and city officials, said the loss has been heavy on the community and the family members of those who were killed.
Officer Eyer, who served in the CMPD for six years and was 31 years old, leaves behind a wife and a three-year-old son.
Chief Jennings said he had just honoured him as "Officer of the Month" in April.
"That's because of his work in the community, because of his work getting guns off the street, and because of how he responds to his cases and how he treats people," he said. "He was the kind of officer you want on your team. And as he demonstrated yesterday, he is the kind of officer you want to respond when you need help."
Poloche, 42, and Elliott, 46, also leave behind families, officials said. Weeks was 48 years old, and is survived by his wife and four children.
"No matter what task you gave him, he always had a smile," said Mr Davis of Weeks. "He was the person you could count on."
North Carolina officials said they have since received several calls from governors of other states across the US, as well as from President Joe Biden and police chiefs from cities in both the US and Canada.
Flowers have since been laid at the police department's front door in honour of the officers.
The incident is one of the deadliest assaults on US law enforcement in recent years.