During the sentencing hearing Friday, Dunn, 47, issued what appeared to be his first public apology to the dead teenager’s family.
In November 2012, Dunn shot Davis at a gas station after an argument involving the music coming from a vehicle carrying Davis and three other teenagers.
Dunn fired 10 times at the vehicle, shooting even as the vehicle pulled away. Davis died soon after being shot, while the two other people in the car narrowly missed being shot themselves.
Dunn returned to his hotel and drove home to Brevard County the next day. He was arrested several hours later.
Prosecutors argued during the second trial that Dunn fired with lethal intent. In both trials, Dunn testified that he responded with deadly force because he reasonably believed his life was in danger.
Mark Berman contributed reporting.