Rusty L. Rumley came to the family's apartment in a public housing complex Wednesday morning under the ruse of needing help moving furniture, Bristol police Chief Blaine Wade said.
Rumley, 26, took Francis Watson - his ex-girlfriend's 43-year-old mother - and her neighbor Roy Malone to a breezeway outside the 10-story Edgemont Towers where he shot them, police said.
Then he returned to the family's eighth-floor apartment and asked his former girlfriend for a drink. As she got it, he fatally shot her boyfriend, Brandon Michael Roskos, 20, and another friend, 53-year-old Danny Wayne Murray, Wade said.
Rumley's former girlfriend, whom police did not identify, managed to close the door and lock him out in the hallway as he tried to reload his .45-caliber handgun, the chief said.
Rumley fled in his pickup truck as neighbors called police.
About an hour later, officers found his pickup about 25 miles away, down a one-lane dirt road just over the Sullivan-Carter county line near Rumley's home in Watauga. The vehicle had been abandoned.
Police caught up with Rumley on foot and surrounded him, then heard a single, fatal shot. A note was found in the truck, but Wade would not release details.
"We are looking into the possibility of him being distraught," Wade said.
The chief said Rumley broke up with the girlfriend, described to be in her early 20s, recently. It could have been "yesterday to two months ago," Wade said.
Rumley had a criminal record and possibly served in the military, but Wade didn't know more. He said police had never received domestic violence reports against him.
All the victims died at the scene except Roskos, who died at a hospital.
This was the first murder in this quiet upper eastern Tennessee town since a police officer was killed in 2004.