On April 17, 1989, Catherine M. "Cathy" Symanowski, of Villa Rica, Ga., separated from her husband, murdered her boyfriend, Robert Lovvorn Herren Jr., 38, of the Hawk community, shooting him at least six times with a rifle. She pled not guilty by reason of insanity but was convicted and served 13 years in prison before being paroled in February 2002.
On December 6, 2012, "Cathy" Symanowski, having been paroled in February 2002, shot her boyfriend Mr. Gerald Palmer, 68, of Red Level, Georgias, multiple times with a small caliber handgun and then turned the gun on herself and committed suicide. Palmer survived.
Source: [Stephanie Nelson, “Woman convicted of Randolph County murder 22 years ago shoots boyfriend, kills self,” Andalusia Star-News (Al.), Dec. 12, 2012]
For links to other cases of woman who murdered 2 or more husbands (or paramours), see Black Widow Serial Killers.