Associated Press:

The US Department of Homeland Security, criticised for failing to check the student status of a Kazakh man charged in the aftermath of the Boston Marathon bombings, has tightened procedures for admitting foreigners with student visas, a US official said
The new procedure is the government’s first security change directly related to the attacks last month.
The order, effective immediately, was issued by a senior official at US Customs and Border Protection, David Murphy. It was circulated on Thursday, a day after the Obama administration acknowledged a student from Kazakhstan accused of hiding evidence for one of the Boston bombing suspects was allowed to return to the United States in January without a valid student visa.
The student visa for Azamat Tazhayakov had been terminated when he arrived in New York on January 20. But the border agent in the airport did not have access to the information in the Homeland Security Department’s student and exchange visitor information system, called SEVIS.