I was reading some things and I think that it is LEGALLY possible for a Bounty hunter to legally arrest an illegal alien who has been ordered deported. Of course you would be setting yourself up to get sued by the ACLU and every other communist pro-illegal group out there.

"Federal law already makes it legal for bounty hunters to capture those ordered deported, but Session's amendment would encourage the practice by establishing 10 centers around the country where bounty hunters could turn in deportees to immigration authorities."

http://www.sfgate.com/cgi-bin/article.c ... B99O41.DTL

In many states the requirements to become a bounty hunter are minimal if even there. In some states anyone can be a bounty hunter just by putting on a badge.

Unlike a police officer, you have no legal protections against being sued, or charged criminally. But legally it's interesting.

I personally wouldn't suggest trying it because of the legal risk involved (besides you never know if the illegal has a gun).