The decomposing body of Donna Kroboth was found on July 11, 1980, in the Lehigh River in North Catasauqua. Officials at the time could not pinpoint the cause of death.
The 18-year-old had been living with her boyfriend but was planning to move back in with her parents in Whitehall Township.
Joseph and Joan Kroboth, who now live in Lehigh Township, have asked Northampton County District Attorney John Morganelli to re-examine their daughter's case.
Morganelli told The Morning Call of Allentown that if his investigation determines Donna was killed, it will be listed as a cold case and reopened. If not, it will remain unsolved.
Information from: The Morning Call, http://www.mcall.com