JMO, and as I posted before, referring to an early press conference, I think Mickey's family is covering all bases from local to international, including the P.I. they hired. He most likely has the ability to investigate nationally as well as internationally.
Why would they do this? Can't conjecture definitively, because this broad scope could mean several different possibilities, i.e. maybe they think persons who were in the vicinity at the time she disappeared have since left the state or country and may have information. Or, they might think that there is a possibility that she is out of the state or country.
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http://theadvocate.com/news/opinion/3208593-123/inside-report-for-july-5
We are asking that the foot searchers who still want to help come in small groups and put fliers around the city, parish, state, and any state or country they go to on vacation, Charlie Shunick wrote, adding that she hopes Mickeys information can be spread across the country, especially along the coast from Florida and the southern United States to California.
We basically want every single inch of the world to be covered with Mickeys face, although we realize that is not actually possible, it is the mind-set we are working with, Charlie Shunick wrote.