By Lisa Maria Garza
(Reuters) - Three decades after a triple homicide case in Iowa went cold, authorities said on Friday they know who did it, but the killer is long dead, executed in neighboring Missouri for murdering a young girl.
Andrew Wessel Six was identified by authorities as the murderer of 20-year-old Justin Hook Jr, his 19-year-old girlfriend Tina Lade, and Hook's mother, Sara Link, 41, who were all found dead in 1984.
A Davis County cold case unit re-examined the case in 2011, and DNA evidence found on the inside of Lade's jeans was later matched to Six, who was executed in 1997 for the death of 12-year-old Kathy Allen in a separate case.
The bodies of the three Iowa victims were found in separate locations in a rural area southeast of Des Moines within a several-day period in 1984, all beaten to death with a blunt object.
Although Six was originally named a suspect after police discovered he and Hook Jr. had had a disagreement over a vehicle purchase, he was never charged with the crimes.
Authorities said they tried to interrogate Six about the triple murders again prior to his execution by lethal injection in 1997, but he refused to cooperate.
(Reporting by Lisa Maria Garza; Editing by Cynthia Johnston and Leslie Adler)