Police should look at men that live in the area and who had their cell phones turned off after 12:30 on July 13. I bet there's a connection there, especially if the phone was turned off until the late evening or the next morning.
Scott Peterson called people shortly after murdering his wife where he pretended, with friends, that everything was normal re their upcoming plans to have couples get togethers. The person that did this to Elizabeth and Lyric may have gone home for supper that day. He may have had the freedom to show up very late in the evening with no explanation. Either way, I suspect that his cell phone was turned off between noon on July 13 and July 14 for several continuous hours. That's two facts, enough to lead to the perp in Blackhawk County and possibly within 12 radial miles of Dunkerton, Iowa, in my opinion ... but it would take a lot of phone log searching ... probably a couple of months to find the person that didn't use his phone after the girls were missing, then acted weird, then got smug.
I hope this has already been done.
eta, Thanks Otto! I appreciate your hard work and your knowledge. I'm learning.