I can't remember this case. It was about a murderer I think. I just remember an older husband and wife driving by and noticing something with a car or whatever. It was the daytime and they got out and tried to figure out what the deal was. This stuck out to me because it got to the point where they had interacted with the suspect/murderer a few minutes before. Then the guy noticed the couple getting on to the papertrail. I remember thinking the older couple could have easily been murdered. I can't even remember who the victim was. Just that the couple were crazy for going so far with no one else around and trying to solve a case when the perpetrator was still around.

Sounds like the Dennis DePue case to me.

http://unsolvedmysteries.wikia.com/wiki/Dennis_DePue

Sounds like the Dennis DePue case to me.

http://unsolvedmysteries.wikia.com/wiki/Dennis_DePue
Yeah that was it. I just went back and rewatched part of the segment. Those people needlessly put themselves in danger if the reenactment is fairly accurate.