Federal investigators said the suspect in the Christmas Day RV bombing in Nashville was killed in the explosion.
FBI investigators said DNA evidence found at the scene matched Anthony Quinn Warner, who was earlier named as a person of interest.
"Anthony Warner is the man believed to be responsible for this horrible crime," Metropolitan Nashville Police Chief John Drake said at a news conference.
Human remains were discovered amid the blast debris, and investigators worked to determine if they belonged to the RV owner. Multiple law enforcement sources briefed on the investigation told ABC News the suspect was identified as Warner of Antioch, Tennessee, a suburb of Nashville.
Douglas Korneski, the special agent in charge of the FBI's Memphis field office, told reporters that investigators were able to make the match quickly after they obtained DNA from Warner's home.
Federal agents arrived Saturday at properties in Antioch connected to Warner in order to conduct court-authorized searches, sources told ABC News. A Google Maps Street View image of Warner's address shows an RV, which appears similar to the one used in the blast, in a fenced-in section of the yard.
Korneski said there appears to be no other suspect involved with the bombing, but the investigation is ongoing.
Authorities believe the RV was parked in front of an AT&T transmission building at 1:22 a.m. on Friday, but it remains unclear if the building was targeted. The Tennessee Highway Patrol confirmed the RV's VIN was registered to Warner.
As investigators work to determine what motivated Warner to set off the explosive, they are also trying to determine whether the AT&T building where the RV was parked was Warner's intended target.
Multiple law enforcement sources told ABC News that investigators are looking seriously at whether Warner may have been motivated, at least in part, by paranoia over 5G cellular technology.
Korneski said his team does not know what Warner's alleged motives were, but "are aware of certain things online, and we're looking at every possible motive." He urged anyone who knew Warner or has any information to use the FBI's tipline.
"These pieces of information will help us determine the suspect’s motive," he said.
More than 250 FBI personnel from at least seven field offices are in Nashville working on the investigation, including special agents, analysts and professional staff, who are conducting interviews, collecting evidence and coordinating with partner agencies, including the Bureau of Alcohol, Tobacco, Firearms and Explosives and state and local investigators.
The high-stakes drama began to unfold about 6 a.m. on Friday when the officers working the late night shift received a call of shots fired inside a building located at 178 Second Avenue North, officials said.
The Nashville police officers being hailed as heroes for saving lives during a massive Christmas morning bombing described on Sunday their quick actions to evacuate buildings as they raced against an eerie recording counting down to detonation and the Petula Clark song "Downtown" coming from a recreational vehicle packed with explosives.
"Immediately, they didn't think about their own lives. They didn't think about themselves. They thought about the citizens of Nashville and protecting them, and they went about knocking on doors," Chief Drake said, as he introduced five of the six officers at a news conference. "Had they not made those efforts, we'd be talking about the tragedy of people and lives lost."
Metro Nashville police officers James Luellen, Brenna Hosey, Michael Sipos, Amanda Topping, James Wells and Sgt. Timothy Miller were described as "heroes" by Drake and Nashville Mayor John Cooper.
"I think they may consider what they did was just a regular part of their duties. But we in Nashville know it was extraordinary, and it's thrilling to have them in our community, and we need to recognize their heroism," Cooper said, before each officer recounted the bombing that damaged at least 41 buildings, ignited several vehicles on fire and left a huge crater on Second Avenue North.
Officer Luellen said he was the first to arrive on the scene and began to check the building for gunfire and requested the security code to get inside. He said that the moment Officer Hosey arrived at the scene to back him up, a recorded voice from the RV parked on the street began reciting an urgent warning.
"The RV started making an announcement somewhere along the lines, don't quote me exactly, but it's, 'There is a large bomb within this vehicle. Your primary objective is to evacuate,'" Luellen said. "I wasn't quite sure what I heard, so I looked at Officer Hosey just to verify we heard the same thing, and then it started over."
He said he radioed his supervisor, Sgt. Miller, who told him to ask every available officer to get to the scene and start to evacuate residents.
As officers Topping and Wells began to block off streets in the area, Luellen, Hosey and Sipos entered an apartment building and commenced knocking on doors and alerting residents of a possible public safety risk outside. He said residents from about six or seven apartments were then instructed to evacuate out a rear basement door.
Luellen said he and his colleagues then went back to the area of the RV to move their patrol cars away from it and make sure no other civilians were in harm's way. He said the RV's drapes were drawn, and there were no registration tags on it.
Hosey recalled that the recorded voice coming from RV then began a chilling countdown, saying, "14 minutes to detonation." She said the warning was followed by the Petula Clark song, "Downtown."
Luellen said that as the voice from the RV counted down to three minutes before detonation, he spotted a man emerge from a nearby building with his dog. He said that just as he yelled at the man to go back inside, the RV exploded.
"I got knocked to the ground. I immediately got up, luckily no injury or nothing like that. I noticed the gentleman in shock with his dog. I checked on him, got him inside," Luellen said.
He said he then ran to check on Miller, who was still inside his patrol car. He said the explosion caused the airbag of Miller's patrol car to go off and that the sergeant was cutting it away when he opened the door.
Hosey recalled that just before the blast, she saw a woman with a stroller and four children on the street. She said the sight "put my heart in my throat."
"I'm asking can I help her… she has a stroller… and I tell her there's a serious threat, and we need you to go. I'm thankful we were able to get her out," Hosey said.
She said she was thrown forward and knocked to the ground by the explosion.
"I made a phone call to a loved one to let them know that I was OK, and then I ran to the intersection to check on Miller and Luellen to make sure they were OK," she said, her voice cracking with emotion. "That's when I got on the radio to make sure Wells was OK."
She said she got no immediate response from Wells.
Wells said the blast caused him to temporarily lose hearing in his left ear, and he didn't hear Hosey and other officers radioing him.
Wells said once he heard the music coming from the RV, he feared officers were being set up for an ambush and began scanning the tops of buildings and parking garages looking for an active shooter.
"At that moment it felt real, and it felt like there was going to be some secondary activity. So every time we came out of a building, we made sure that we were looking around and checking high areas, just making sure nobody was peeking around and looking at us," Wells said.
He said that just before the blast, he was walking back toward the RV and "I literally hear God tell me to turn around and go check on Topping, who was by herself."
"For me, it felt like I only took three steps and then the music stopped, and as I'm walking back towards Topping now, I just see orange and then I hear a loud boom," Wells said.
He said the explosion caused him to stumble.
"I was just telling myself, 'Stay on your feet, stay alive,'" Wells said. "I just take off in a full out sprint, and I'm running toward Topping to make sure she's OK. We kind of meet in the middle, and we just grab each other and checking each other."
He said he yelled to Topping to get her gun out in case they came under fire.
"It was just weird," Wells said. "It felt like something out of a movie."
Topping added that when she grabbed Wells, "I've never held someone so hard." She said hearing Wells voice in that chaotic moment "is what got me to see my kids on Christmas."
ABC News' Aaron Katersky, Josh Margolin and Jack Date contributed to this report.