This mini-series captures Jack Lemmon in a strong role as a real historical figure. Governor Slaton of Georgia risked (and ultimately lost) a promising political career in his search for the truth as to what really happened to Mary Phagan. Lemmon is heroic in an understated way----very different than many of the manic-like comedy performances that conspicuously dotted his long career.
The story was filmed before in 1937 by Warner Brothers with Mervyn LeRoy directing as "They Won't Forget." This is the film that launched the career of Lana Turner as a major sex symbol. She played the very small Mary Phagan-like role when just a young teenager---and who could forget her famous stroll through town as she strutted her sexy stuff just before her murder? In "They Won't Forget," the story was changed significantly to eliminate any reference to the Leo Frank-like character as a Jew. Instead, he was depicted as a teacher (not a pencil factory manager) with apparently a Christian background.
"They Won't Forget" was a typical Warner Brothers social drama of the 1930s. It fudged on the facts but was quite gripping and engrossing. Claude Rains may have been somewhat over-the-top as the prosecuting attorney---but he commanded your attention.
On the other hand, "The Murder of Mary Phagan" stays much closer to the true story. It's interesting to compare the two films to see just how much easier it was in 1988 to tell the whole narrative of the Leo Frank case than it was in 1937.
For another source of information on this remarkable historical event, seek out Harry Golden's fine book of many years ago---"A Little Girl is Dead."