and who the heck was earl john bourdeau? s archives looking for any old story about the man, or the murder. >> we couldn't find anything. so, i just did a google search and came up with bourdeau in iowa. >> the bourdeaus lived in davenport, iowa, along the mississippi river, in their very same house where earl grew up. back then, they called him duke, a handsome, friendly, midwestern kid. this is his brother dennis. >> he was the pride of the family. >> your big brother? >> yeah. [laughs] yeah. i looked up to him a lot. we were kind of each other's protectors. >> duke joined the marines during vietnam, but was stationed in the philippines. where he met a pretty young filipina named sonia, who sang in a nightclub near the base. and she was worth writing home about. dennis kept the letters. and it wasn't long before he got a call from duke. >> he said that he gotten married. >> holy cow. he fell in love at first sight or something? >> i think he must have. it was almost a big secret. >> a few months later, duke brought the secr