The terror watch list is a secretive government database containing about 450,000 names of those suspected of having financial, recruiting, or any other tie to Al-Qaeda-type groups. Since these suspects haven't necessarily committed a crime, however, they're free to go about as they please to a certain degree: including buying a gun if they pass a standard background check.
In 2010, 247 people "suspected of ties to terrorism" bought firearms legally, according to FBI figures obtained by the Associated Press. And over the past six years, 1,453 suspects had attempted to purchase a weapon legally, with 90 percent able to do so. Those numbers are extra chilling when you consider that Faisal Shahzad, 2010's attempted Times Square car bomber, was one of those who had bought a gun.
The AP's report is only the latest salvo in a long-running debate that's pointed out the incongruity of people with purported terrorism ties being able to purchase weapons. The Justice Department's hands are tied though--it's a Second Amendment issue. The DOJ responded to the AP through a spokesman saying this:
The department is committed to doing everything within its power to keep firearms out of the hands of persons who may intend to use those weapons to commit terrorist acts...To the extent Congress wishes to provide the department with additional tools that would improve the status quo, we remain committed to working with them to achieve that goal.