Johnson, 77, and his wife, Sara, 68, were members of First Baptist Church and died in the shooting, one of their daughters, Kati Wall, told CNN.
The couple had six children and and celebrated their 44th wedding anniversary on July 27.
A relative set up a GoFundMe page that said the Johnson’s had several grandchildren and were also expecting four-great grandchildren.
According to the page, Dennis Johnson was an appointed church elder and served in the US Navy Reserves and the Army National Guard.
Johnson later joined the American Legion. Friends and family described the Johnson’s as a loving couple and devoted members of the First Baptist congregation for more than a decade.