Bronze Star recipient killed by police did not follow officers' orders to drop his gun, police chief says Gary Black, a Vietnam War veteran, may have been hearing impaired, police said.

The Purple Heart and Bronze Star recipient who was killed by Colorado police after he saved his grandson from a home intruder did not follow officers' orders to drop his gun, Aurora Police Chief Nicholas Metz said in a press conference Thursday.

Richard "Gary" Black, 73, shot and killed the suspect, 26-year-old Dajon Harper, as Harper allegedly "violently and seriously" assaulted Black's 11-year-old grandson in the bathroom of the Aurora home early Monday morning, Metz said.

Officers heard shots fired inside the home within three minutes of arriving on the scene, Metz said. When Black came into view, they observed that he had a firearm and instructed him multiple times to "the drop gun and to show his hands," Metz said.

After the shooting, investigators learned from Black's family that the Vietnam War veteran had "a significant hearing impairment."

"I don’t know what he was able to hear and not hear," Metz said.

About 3 days after the shooting, Metz, having reviewed the body camera footage and 911 dispatch calls, shared more details on what transpired early Monday morning when Black was killed.

A house party gone wrong

Police began receiving 911 calls around 1:30 a.m. Monday from a house party Harper attended across the street from Black's home. The calls detailed that Harper had become "out of control," Metz said.

Harper had been "acting irrationally" and damaged cars in the area, and even injured himself in the process, Metz said.

It was difficult to get information from the callers at that point due to the commotion, Metz said. One person who hung up and was called back by emergency dispatchers told them, "I don't know where I am. Just get here," Metz said.

At that point, there was "still no description provided to our dispatch as to what this person looked like who was out of control," Metz said.

Harper then allegedly ran across the street to Black's home and banged on the "very solid door" so hard that he knocked it off its hinges and entered the home, Metz said.

A number of people ran in after him in an effort to get him out of the house, but they were not able to, Metz said.

Harper allegedly dragged Black's grandson into a bathroom

After going into Black's home, Harper allegedly dragged Black's 11-year-old grandson into a bathroom and "violently assaulted" him, Metz said, declining to describe the crime further.

When Black's wife called 911, she told dispatchers that the "man who entered was trying to drown" her grandson, Metz said, adding that her 911 call was "incredibly difficult" to listen to because of all of the screaming that could be heard in the background.

Black's wife told dispatchers that a person was in the bathroom "hurting the child," and that there "was lots of blood everywhere," Metz said.

When the dispatcher asked Black's wife whether there were weapons, she replied, "No," Metz said.

Another 911 from a family member of Harper's indicated that he was "on drugs," Metz said, but it is unclear what kind of drugs the caller was referring to.

Police arrived to an "incredibly chaotic situation."

The body camera video worn by the officer who shot Black began as he and another officer responded to the incident, Metz said.

Once they arrived and got out of the car, they encountered several people yelling in front of the home who appear "very agitated" and "very emotional," Metz said.

The group informed the officers that they tried to get into the home and that Harper was allegedly "hurting the child," Metz said.

As the officers walk up to the home, Black's wife can be heard saying, "He has a gun," Metz said, but it is unclear who she is referring to.

As officers walked toward the house, they heard shots fired, "within 33 seconds of their arrival on scene," as well as "a lot of screaming inside the home," Metz said.

After taking a step back from the front door, the officers saw Black emerge from behind a wall about 15 to 20 feet away inside holding a gun in one hand and a flashlight in the other hand, Metz said.

For the next 13 seconds, officers gave commands to Black to drop the weapon and show his hands, but he didn't, Metz said.

Ten seconds later, Black walked toward officers with the gun and flashlight still in his hands, prompting the officer to fire four rounds at him. It is unclear how many times Black was struck.

After Black fell to the ground, the officer dispatched for medical attention and continued to give Black orders to show his hands, Metz said. He then directed other officers to provide aid to Black as he and two more officers continued "forward to where the screaming was coming from."

While on the ground, Black was able to tell officers that his son and grandson were in the bathroom, Metz said.

When the officers got to the bathroom, they found a "deceased, nude man on the floor," and the 11-year-old and his father in the bathtub -- a mere 2 minutes and 27 seconds after they arrived on the scene, Metz said.

The child was screaming that Harper "was the one that assaulted him" and gave "pretty graphic details" of what happened to him, Metz said.

Once the scene was secured, Black was transported to a local hospital, where he died from his injuries, Metz said.

Authorities are not yet releasing the 911 calls or body camera footage at this time, at the request of prosecutors and Black's family, Metz said. The footage will be released at a later time, once the investigation is over and a forensic review has been conducted on the portions that are inaudible, Metz said.

"We are supportive of releasing it," Metz said. "I want to make that very clear."

The officer who shot Black is a veteran himself

Metz did not release the identity of the shooting officer.

The officer has been with the Aurora Police Department for three years and had just been reviewed for another police-involved shooting that took place 30 days prior, Metz said. He returned to duty 18 days after the shooting after receiving peer support and spending time with the department's psychological services, Metz said.

Metz chalked the proximity of the two shootings to coincidence and praised the way he handled the situation.

"We can't control the kinds of situations that our officers are going to be called to -- whether it's a week later or a year later," he said. "I feel bad for this officer. Unfortunately, lightning struck twice for him. But, when I watched that video, I'm impressed at his ability to remain calm."

Metz disputed claims that the officers acted recklessly in their response.

"They were not reckless," he said. "These officers responded, again, how I would expect them to respond in this situation, given the limited amount of information."

The shooting officer, who works the graveyard shift patrolling northeast Aurora, has been placed on paid administrative leave -- as have the other officers involved, Metz said. He has had no prior internal affairs complaints, Metz said.

Black's death "has been devastating" for the officer, a military veteran himself who has served on two deployments, Metz said.

Black's family is "incredibly traumatized."

Black "saved the family's life that night, in particular, his young grandson," Metz said.

The grieving family is "incredibly traumatized," Metz said.

Black received his Purple Heart and Bronze Star medals for courageous service with the U.S. Army in Vietnam, where, according to his family, he was taken prisoner and injured multiple times. After he returned from the war, Black worked as a federal employee before retiring in 2015, Metz said.

"My dad was a hero, period," Black's stepson, Chad Hayashi, told ABC News on Wednesday. "He's been a hero in this country since 1966, and he needs to be recognized as such."

Metz described his meeting with Black's family on Thursday morning as "helpful" and "healing." There, he spoke with Black's wife, who regaled stories to the police chief about how they met, how long they'd been together and "funny stories" they shared throughout their life together, Metz said.

"The family acknowledges that the responding officers did not receive a description" of the suspect, Metz said.

Black "deeply appreciated law enforcement," Metz said.

Through local organization Cops Fighting Cancer, Black's wife would create quilts for young patients battling serious illnesses at local children's hospitals, the family's letter stated.

The police department "continues to remain heartbroken" over Black's death, he said.

Harper has an "extensive and violent background"

Harper had been arrested twice on suspicion of first-degree murder, once in 2011 and again in 2013, according to Colorado Bureau of Investigation records obtained by ABC Denver affiliate KMGH-TV. Both times the charges were either dropped or reduced, according to the CBI records.

The families who lived in the two homes did not know each other, Metz said.

"It appears to be completely random," he said of the encounter.

ABC News' Bill Hutchinson and Clayton Sandell contributed to this report.