CHARLOTTE, N.C. -- The brother-in-law of the mayor of Columbia, S.C., was shot and killed Friday afternoon outside a Charlotte store, police said.

Donald Gist Jr. was pronounced dead in the parking lot of the Queens Mini-Mart north of Charlotte's Uptown around 1:15 p.m. Friday, investigators said.

Detectives think Gist was killed by someone he knew, but they have not named a suspect or given a motive for the killing.

Gist's sister is Circuit Court Judge DeAndrea Benjamin, who is married to Columbia Mayor Steve Benjamin.

"The shock and sadness of the past few hours have been difficult to bear. We will remember Donald as he was: a loving husband, father, son and brother," the Benjamin and Gist families said in a joint statement.

The families said they have confidence Charlotte-Mecklenburg Police will find Donald Gist's killer. They asked for prayers as they deal with the death in the days and weeks to come.

"We will continue to lean on our faith in Almighty God and each other as we try to make sense of this tragedy," the families' statement said.