White, 54, was convicted in December of second-degree manslaughter and a weapons charge.
"Nice message it sends to society that as long as you're black and there's a problem at the end of your driveway you can grab an illegal handgun and shoot someone in the face and get away with it," an infuriated Daniel Cicciaro Sr. told reporters while dozens of supporters sobbed nearby.
"Well, let's see what happens when Aaron White gets shot, and see how the laws are," Cicciaro said, referring to White's teenage son.
Suffolk County District Attorney Tom Spota said a discussion of the courthouse incident with Suffolk County Police Commissioner Richard Dormer has resulted in the assignment of additional police protection of the White family residence.
At least 18 officers kept order in the packed courtroom; several hundred people awaited the verdict in the hallway. Afterward, supporters, including sobbing teenage girls, gathered with the Cicciaro family outside the courthouse.
White was led away in handcuffs, but his attorneys planned to seek approval from a higher court to let him remain free pending appeal.
"I've always remained remorseful about this incident," White told the judge.
At the trial, the defense invoked the nation's violent racist past in arguing the shooting was justified, referring to the teenagers as a "lynch mob."
The defense said it perceived Cicciaro's remark outside court as a threat and demanded an immediate investigation. Prosecutors said they were considering referring the matter to police.
White testified that he was trying to protect his family on a hot August night in 2006 when he got his gun after a group of angry white teenagers turned up at his house late at night to fight his son. He claimed the weapon discharged accidentally, killing Cicciaro.
Cicciaro, who had a blood-alcohol reading above the legal limit for driving, was just three inches from the pistol when he was shot in the face, a medical examiner testified.
White said his 19-year-old had wakened him around 11 p.m. to tell him he had been feuding with other teens after being asked to leave a party and a group of the teens was headed to their house in Miller Place, a predominantly white community on eastern Long Island.
