Investigators identified him on Thursday as 35-year-old Daniel Shacklett.
The standoff unfolded on Ramsey Road off of Route 202 when New Castle County Police responded to a shots-fired call around 3:50 p.m.
Police said a man called 911 and reported seeing his roommate, now identified as Shacklett, with a gun and hearing him begin shooting.
According to police, officers arrived to find Shacklett inside the home still actively firing a weapon.
"The person inside the home was still actively shooting a weapon and at that time because of the situation, our crisis management group was dispatched and responded to the scene," said M/Cpl. Richard Chambers of New Castle County Police.
A roughly four-hour standoff followed as crisis negotiators attempted to get Shacklett to come outside peacefully.
Police said that around 7:45 p.m., Shacklett exited the home carrying a shovel.
"He started swinging the shovel towards the officers. At that point, officers deployed less-than-lethal equipment towards him," Chambers said.
Police say officers tried to subdue Shacklett with a Taser, but he went back inside the house, then came back out armed with knives and charged toward officers.
"He advanced towards the officer, and at that point the officers discharged their department-issued weapons," Chambers said.
Phillip Lionti and his son recorded video of the shooting Tuesday night before 8 p.m. Lionti said he heard loud explosions during the incident.
"I was also hearing the two big loud bangs that sounded like a bomb going off, one outside, one inside," Phillip Lionti said.
Fillipo Lionti described his reaction as the gunfire erupted.
"I was just standing out there listening and then I heard the shots go off and I went back inside. It was scary," he said.
Police said Shacklett was pronounced dead at the scene. Evidence markers remained outside the home as the investigation continued into Wednesday.
Authorities said no officers were injured, and the roommate who called 911 was unharmed and safe.
Neighbors said the incident has left them shaken.
"Stressful knowing that someone passed away right there," Fillipo Lionti said.
The officers who fired their weapons have been placed on administrative leave as the investigation continues.
Anyone with information is asked to contact Detective Lieutenant Seth Polk of the Criminal Investigations Unit at (302) 395-8112 or Seth.Polk@newcastlede.gov. Information can also be submitted by calling the New Castle County Division of Police non-emergency number at (302) 573-2800.