The US government has several ways of importing foreigners besides just letting them slip in through Arizona and Texas. http://travel.state.gov/visa/ covers most of that. There’s also a refugee or asylum system. Rossi became a US citizen, so how did he get in? Please read the following section about prohibited classes and tell us how it was Rossi could commit the string of crimes you say he commited and still get into the US, or, if he was already here, stay here: http://travel.state.gov/visa/frvi/ineligibilities/ineligibilities_1364.html
Rossi became a US citizenSource?
so how did he get in?According to you, Jimmy Carter gave him a visa. I haven't seen any evidence of that other than Rossi's autobiography, which has other self-promoting lies.
If Rossi got a visa (or even became a U.S. citizen) during the Carter administration, then that was at least a decade before his convictions in Italy.
I do know that the oldest and most respected newspaper in Italy has a decade worth of stories about Rossi's numerous crimes and convictions.
All I know about Rossi's visa and supposed citizenship is Rossi's self-serving autobiography and your uninformed guesses.