Hairston, the 26th overall pick in the NBA draft, said Friday at introductory press conference that he "fully regrets everything that happened" around benefits and eligibility issues while playing at North Carolina.
Hairston said he's matured over the past year.
"I've some bumps in the road that I had to overcome and I feel like I've done that," Hairston said.
Hairston rose to prominence as a sophomore when he became a midseason addition to a four-guard starting lineup, becoming UNC's leading scorer and flirting with entering the NBA draft before opting to return to school.
But he never played again for the Tar Heels. He sat out the first 10 games last season while the school worked to resolve eligibility questions for receiving improper benefits, tied largely to the use of rental cars linked to Durham felon and party promoter Haydn Patrick "Fats" Thomas.
Authorities cited Hairston in May and June 2013 while he was driving vehicles linked to Thomas, the second time leading to a later-dismissed charge for misdemeanor marijuana possession.
The school decided in December it would not seek reinstatement from the NCAA for Hairston due to several violations, ending his college career and ultimately sending him to the NBA Development League.
He said he's put the past behind him and his focus is on helping the Hornets become "a hundred times better."
General manager Rich Cho introduced Hairston and power forward Noah Vonleh from Indiana, the team's other first-round draft pick, at a press conference at the team's downtown arena.
Cho said the team did plenty of research on all of the team's potential draft picks, including Hairston. He said after speaking with Hairston he walked away confident he wouldn't be a distraction.
"He was pretty forthcoming with some of the mistakes he's made," Cho said. "I think that's a positive. We're giving him a fresh start and I think he will take advantage of that."
Hairston has a chance to make a big impact for the Hornets.
Charlotte was 26th in the league last season in 3-point field goals made, which happens to be Hairston's biggest strength.
"He's got range, strength and physicality," Hornets coach Steve Clifford said. "I think the quicker he gets in here and gets to work we will lock in on two or three areas of this game. I think he has a chance to be a very good player."
But Hairston is out to dispel the notion he's just a jump shooter.
"I want to prove I can be a versatile scorer and not just a shooter," Hairston said. "I want to show I can score in different ways."
Hairston averaged 21.8 points for the Legends in 26 games and twice scored more than 40 points while shooting 35.8 percent from the NBA-length 3-point arc.
He said playing in the NBA Developmental League helped him mature as a person and got him used to the professional basketball.
"I had a chance to start over in the D-League and that put me months ahead of everyone else" coming into the league, Hairston said.
Hairston joins the Hornets and is expected to back up Gerald Henderson.
North Carolina coach Roy Williams had previously called Hairston's departure one of the toughest things he's been through during his career.
Williams said in a press release Thursday night he was "ecstatic" for Hairston.
"I am happy that he will still play in state and for another Tar Heel, Michael Jordan," Williams said. "Life has given him another opportunity and he will take great advantage of that chance."
Cho said the Hornets were thrilled to get Vonleh with the No. 9 pick after many had him projected in the top five mock drafts.
However, it's clear Vonleh will have plenty of competition when it comes to playing time.
Cho said the decision to draft Vonleh doesn't preclude the team from attempting to re-sign starting power forward Josh McRoberts, who opted out of his contract earlier this month. Cody Zeller, the No. 4 overall pick in 2013, showed good progress as a rookie and is McRoberts' primary backup.
Cho also said the team would like to add a scorer and two more point guards to back up Kemba Walker in free agency. The Hornets are expected to have some interest in bringing back free agent Ramon Sessions, who was the traded to Milwaukee last season.