Who needs a passport?

Bruce Redmon, the man who is a suspect in his wife's untimely and suspicious death in Cancun Mexico, somehow crossed the border back into the U.S. without a passport. Now he hasn't been charged with his wife's death, but the Mexican government did take his passport and tell him not to go anywhere. Who cares? He showed back up in L.A. yesterday. No passport needed. His wife's family is furious and distraught. I can understand why. I can just imagine what would happen if an everyday American citizen tried to get back across the border without a passport!