Here's the visa program Sayfullo Saipov used to get into the country
It's an immigration program that's been around for more than two decades, offering a limited number of visas to people from across the world.
Well known abroad, it has received little public attention in the U.S. - until now.
On Wednesday - a day after a rented pickup barreled down a crowded bicycle path in Manhattan, killing eight people - federal officials said the suspect in the attack, 29-year-old Sayfullo Saipov, had entered the country from Uzbekistan in 2010 through
