Thanks for the quick replys, I'll keep you updated as to what happens if anything.

Generally, a failed polygraph alone is not considered to be probable cause to arrest someone, and, as mentioned polygraph results are generally not admissible as evidence in criminal cases.

In addition, the Employee Polygraph Protection Act prohibits private employers from taking adverse action against an employee solely on the basis of polygraph results (or the employees refusal to submit to a polygraph interrogation).

Depends on your state but most polygraphs are not admissible in court. The only way he would be arrested is if he made an admisson during the polygraph. Although if he is terminated soly on the polygraph results he may have a valid civil suit against the company.

Anxiety

My brother works for a moving company, during a recent move the owner claimed her ring which she left on a kitchen counter went missing in a housefull of movers and neighbors. Cops were called and they (the cops) asked my brother to come in for a polygraph.
The reason I think they asked him is hes covered in tattoos. There are no witnesses to any ring being taken. I told him not to take the test due to unreliable results. 
My brother said he didn't do it (take any ring) and didn't want to lose his job(this is his first steady job in years) and here in Fl small business owners can fire an employee for any reason. I didn't think this would be a reason but I do know of people that were fired for less. In any event he said he had no problem taking the test and ofcourse they told him he was found to be deceptive or I wouldn't be here.
My question is, I think they are just trying to see if he'll admit to taking it, but if the test really came up deceptive what can be done w/ it? Can he be arrested based soley on the test w/ no additional evidence?
Thanks for your help,
Ken