Barack Obama praises Zaevion William Dobson as 'a hero at 15'

Barack Obama described Zaevion William Dobson, a high school football player who was killed as he shielded three girls from gunfire, as a "hero" in a message posted on the president's official Twitter account.

The shooting that killed Dobson, 15, began Thursday night in Knoxville, Tennessee. Police said men drove to Dobson's neighborhood in retaliation for an earlier shooting and "randomly fired multiple times."

Obama took to Twitter on Saturday to praise Dobson and weigh in on the shootings, which police investigators believe to be gang-related.

Rob Black, Dobson's football coach at Fulton High School in northern Knoxville, called Dobson a "fine, fine young man." Knoxville Police chief David Rausch said Friday that investigators have not found a reason that Dobson would be targeted.

"Unfortunately, they picked a random group of young men and women who were just hanging out and trying to prepare to celebrate the holiday," Rausch said.

Dobson was a sophomore at Fulton High School, which brought in counselors to speak to students taking makeup tests Friday morning.

"He was really one of our success stories," Knoxville Mayor Madeline Rogero said. "Involved in sports, a mentee of one of our organizations in town. But still he falls victim to this."

Information from The Associated Press was used in this report.