Thanks for the disturbing article by Jed Morey. Fortunately he provided a citation to 10 USC 18 MILITARY SUPPORT FOR CIVILIAN LAW ENFORCEMENT AGENCIES. I read all of the citation, as much as such can be read, and did NOT find his quoted passage there, even after searching within it for keywords.
I did find it on-line;
When I spot checked inside these URL for keywords and tricky phrases, I found such as "when permitted by reference foo.bar." I suggest checking with SNOPES.