In late December of 1979 two long-time friends took off from Moline Illinois to run an errand, but the two men failed to make their last stop and vanished without a trace. About 4 months later they were found dead and the location of their bodies were right under police's noses for months. These are the murders of Gary Harker and Cody James.

Sources: 

newspapers.com

Iowacoldcases.org by Jody Ewing

"Police search for 3 suspects linked to deaths" The Quad-City Times Wednesday May 14, 1980 By: D'Anne Dodd page 6

"Police renew 25-year-old slaying case" The Quad-City Times Sunday December 19,  2004 By: Todd Ruger page 1 & page 3

"Murder weapon found" The Dispatch Wednesday May 14, 1980 page 7 

Cody James Obituary The Dispatch Monday April 28, 1980 page 5

"Auctioned truck holds 2 bodies" Quad-City times Friday Apri 25 1980 page 1 by: Jim Kosowski

"Police link soil, deaths" Quad-city Times Tuesday June 3, 1980 page 5 

"Slaying probe tests offer little help" Quad-City Times Tuesday August 5, 1980 page 3

"Search for David Harker ends" The Rock Island Argus Thursday October 3, 2013 page 1 by: Tyler Langan

"Elder Harker's brother was found murdered in 1980" The Rock Island Argus October 2, 2013 page 1 by: Tyler Langan

"Man gets 2 years for hiding body" The Des Moines Register Friday October 7, 1977 page 3