I don't know of any public lynchings, in the real sense of the term, in the 60's South. Their heyday was from 1900 to the 40's, gradually diminishing with each decade.
The term has sometimes, inaccurately, been used when whites murdered blacks and got away with it due to public and law enforcement attitudes favoring their actions.
There were three actually, in 1961, 1963, and 1964 (plus the usual unexplained "disappearances" of young black men). You are correct that the practice was beginning to die out by the 1940s.