"Why would you shoot at random bystanders?
"For nothing ... Zae, he was an awesome kid brother, awesome brother. Just know that I miss him. I miss my brother."
One of the girls whose life was saved by Dobson's brave act took to Twitter to pay tribute to him.
Dobson's death was connected to several other incidents on the same day, said Knoxville Police Chief David Rausch. Forty-six-year-old Lisa Perry was shot in her apartment, before her 23-year-old son, Brandon Perry, drove to Dobson's neighbourhood with friends and began randomly firing.
He later died from gunshot wounds following a car crash, while his mother is expected to survive.
"These cowardly and senseless acts of violence must stop," Rausch said. "We should be preparing to celebrate the Christmas holiday, but now we have two men who are dead.
"Unfortunately, they picked a random group of young men and women who were just hanging out and trying to prepare to celebrate the holiday."
Dobson, a sophomore student at Knoxville's Fulton High School, was a talented sportsman
"He was really one of our success stories," said Knoxville Mayor Madeline Rogero.
"Involved in sports, a mentee of one of our organisations in town. But still he falls victim to this."
Coach of Fulton's football team, Rob Black, was full of praise for the popular teenager, calling him a "fine, fine young man".
"Only a sophomore, but a very contagious young man who was very liked by his peers and his teachers," Black said. "Going to be a tough time as we leave from here and go meet with our football players."
Two men who fled the crash that killed Brandon Perry were arrested, but one was released after being questioned by police. Authorities charged 20-year-old convicted felon Christopher D. Bassett with possessing a weapon and violating probation.