A national forensic expert calls the newest round of DNA testing in the 25-year-old murder conviction of Wayne Williams “another nail in his coffin” that reinforces the credibility of the jury’s 1982 guilty verdict against Williams.

Recently completed tests of eight human hairs recovered in 1981 from the body of one of the slaying victims represented Williams’ last chance to secure new evidence that might have discredited forensic links tying him to 12 slaying victims at his 1982 murder trial. The Fulton County district attorney released the report of the DNA test results Wednesday.