Authorities say the officer, 37-year old Oneil Peart, was standing in front of a liquor store at 247 Straight Street at about 1:30 a.m. when he was shot in the back and side.
He was armed at the time but unable to return fire due to his injuries, according to police.
The officer is listed in stable condition.
Authorities say Peart was working at the store as a security guard and had gone outside to break up a crowd. Moments later, a vehicle pulled up and at least one person in the auto began shooting.
It's not yet known what sparked the shooting or how many shooters were involved.
Peart has worked at the sheriff's department for about six years overall.
There have been no arrests.