Under President Barack Obama the agency was under the microscope for reform, but under the Trump administration any progress toward that goal has been halted.
While immigration officials announced this week they won't urgently seek to deport undocumented residents protected by the DREAM Act, the policy's future is far from certain.
Under the Obama administration, agents had discretion in cases of immigrants with gravely sick children. Under Trump, officers are told to enforce the law "to the greatest extent practicable."
After studying four decades of terrorism, Aaron Clauset thinks he's found mathematical patterns that can help governments prevent and prepare for major terror attacks. The U.S. government seems to agree.
Outside the U.S., biological labs follow few if any security regulations. A Sandia National Laboratory team works to help those labs prevent deadly microbe releases, accidental and deliberate.
An expert on electronic privacy walks through the possibilities and perils on a national online security system designed, in part, by the U.S. Department of Homeland Security.
A Penn State power-system expert cites laws of physics to pull the plug on worries that a terrorist attack on a minor substation could bring down the entire U.S. electric grid.