I went through that interchange this morning just as the news came out. There was a police SUV stopped on 380 northbound with lights on but no other LE presence that I saw. There’s no unusual LE activity on I80 between Iowa City and Des Moines either.
Regarding DNA, at the Dayton press conference yesterday the investigator said the crime lab is really backed up and getting DNA tested typically takes months. They rushed the test of the blood at the recent crime scene because it's obviously time critical, but testing MK re the Evansdale girls...
I think he had them both at the same location, then the girl escaped and Kathlynn didn't, and then MK left with Kathlynn and took Kathlynn to some other location.
If you look up that home address listed on the sex offender registry on the Hamilton County Assessor website it shows that it is owned by MK and his wife, and was purchased in February of this year.
Pictures here http://blogs.desmoinesregister.com/dmr/index.php/2013/05/21/suspect-in-dayton-girls-disappearance-twice-convicted-for-kidnapping-assault/article taken from the sex offender registry.