It's a fairly narrow technicality: Perkins owns two homes; both are in Shreveport but they are located in different electoral wards. He is registered to vote with the Shreveport home as his primary residence, but his "homestead exemption" is on his other home. This goes against state law which states that candidates other than U.S. Senators and Representatives must be registered to vote in the same precinct that they claim a homestead exemption in, unless they reside in a nursing home or veteran's home. Perkins argues that he corrected the issue as soon as he was made aware of it and was never actually disqualified from voting, which is what would formally disqualify him as a mayoral candidate.
Basically, I don't think any moral turpitude attaches to it; the guy's basically just guilty of, "Failed to read the fine print, assumed my staff would double check it."