the rassmussen's insist early in the investigation they told the lead l.a.p.d.etective about sherry's troubling encounters with john's ex-girlfriend. >> i told the detective, not once, but probably 15-20 times. and he said, the trouble with you is you have been watching too much tv. >> coming up, old he was offers new clues. >> the suspect made it appear to look like a burglary. they staged it to mislead the initial investigation in 1986, she was executed. >> when "dateline" continues. ♪ >>> years had passed and no arrests had been made in the brutal 1986 slaying of nurse and new ll newlywed of sherry rasmussen, the trail kept getting colder. sherry's parents offered to have the saliva sample of the bite mark tested for dna, they even would pay for it and the l.a.p.d. declined. >> they said, we don't have a suspect, if we center a suspect, and we have their dna, then we have something to match. >> and the case sat for another decade. then the newly formed cold case unit was conducted dna tests on unsolved cases and one of them was the murder of sherry rasmussen,