Those men are believed to have been two of the hijackers of the two jetliners that slammed into the World Trade Center in New York on Sept. 11, killing almost 3,000 people.
The paperwork that arrived in the mail on Monday — the six-month anniversary of the attacks — contained both men's student visa approval forms from the Immigration and Naturalization Service.
Russ Bergeron, an immigration agency spokesman, attributed the embarrassing delay to a backlog of documents at a federal paperwork processing center in London, Ky.
He described the paperwork as "backup notification." He said the INS had already notified the men and the school last summer about the approvals.
Atta and Al-Shehhi trained at Huffman in Venice, Fla., in 2000 and early 2001, and were aboard the separate flights that struck the trade center towers.
The two initially entered the United States on visitor's visas but applied for M-1 student visas, given to immigrants attending technical schools in the United States. Foreign students are generally allowed to study in the United States as long as they apply for student visas, said Russ Bergeron, a spokesman for the immigration service.
The INS approved Atta's request in July 2001 and Al-Shehhi's request the following month, Bergeron said.
"The important thing to recognize is the decisions to change their status were made ... before Sept. 11, and at the time there was no information made available to INS regarding these people and their link to terrorism," Bergeron said.
But Rep. John Conyers, the top Democrat on the House Judiciary Committee, said the notification was a sign of the Bush administration's "misguided focus in pursuit of homeland security."
"I am astonished that while the INS is fixated on detaining and rounding up countless Arab-Americans without any justification, it has failed to take basic steps to ensure that visas are not issued to known terrorists," said Conyers, D-Mich.
Atta and Al-Shehhi were cleared to stay in the United States until Oct. 1, 2001, according to the forms, which were provided to The Associated Press by Rudi Dekkers, owner and president of the flight school.
"When they hit the buildings they were approved to be here," Dekkers said.
U.S. authorities believe Atta, 33, was aboard American Airlines Flight 11, which struck the north tower of the trade center, and that Al-Shehhi, 23, was aboard United Airlines Flight 175, which struck the south tower 17 minutes later.
Dekkers said Atta and Al-Shehhi completed the paperwork on Aug. 29, 2000, just before they began their six-month flight instruction program at the school.
The forms, filled out by an assistant at Huffman, indicated that both men met the English language requirements to study at the school. Atta listed his nationality as Egyptian, while Al-Shehhi said he was from United Arab Emirates.
On the form, Atta's name is spelled "Mohomed." The documents indicated the academic term lasting up to 12 months would cost $27,300.
Both men studied at the Technical University in Hamburg, Germany, received pilot training at Huffman and practiced their flying on a Boeing 727 flight simulator in the Miami suburb of Opa-locka.