I think bc LE stated that they didnt appear to be linked, and they have the facts to draw that conclusion. I dont think they have any reason to mislead the public about that. Personally, I think the 13th date is just a coincidence. It's tempting to want to relate the two, but I just don't think they are connected. Just my two cents.
At the risk of being thought of as completely over the top about this, I will repeat my assertion that it's not just the 13th of the month that connects these murders, but more the date reversal.
The Iowa cousins were abducted on 7-13-12. Writing those numbers backwards in exact order is 2-13-17. That's the date Abby and Libby were abducted. I cannot believe that is mere coincidence. Imo, it is so far out of the range of coincidence, it would be like a bunch of monkeys jumping up and down on a computer keyboard and producing a book. I cannot dismiss it.
Also, the Iowa cousins were found in Seven Bridges park, near the water's edge. Abby and Libby were abducted from the Monon High Bridge and found near the water's edge.
I believe the perp is a serial killer who killed both sets of girls. He appears to be fixated on finding young girls in sets of two, on the 13th of the month to be his victims. He is also obsessed with finding a wildlife area with 'Bridge' in it's name, and leaving their remains near the water's edge.
I believe this is his known M.O. There may be more to it that LE has not revealed, but imo, this much can be clearly deduced.
As for LE, I don't believe they were intentionally misleading the public. Though they have likely been looking for any connections from the beginning, I imagine they are very reluctant to show their hand.
It would be premature. That's one thing that seems to be true about all LE investigations. Their primary goal is to catch the perp, and not do anything to jeopardize their cases. Keeping the public informed is secondary. Therefore, every word to the public is very carefully chosen.
I interpret their statements to mean, "This is all we want you to know at this time."
Not that what they say, is ALL they know.
Again, only my opinion, and I'll be more than happy to be wrong if LE would just nail this guy!