the broader economy. >> woodruff: then, jeffrey brown reports on the first suspected u.s. drone strike since president obama laid out new guidelines for such attacks, this one killing a top leader of the pakistani taliban. >> ifill: a new survey finds mothers with children at home are now the top breadwinners in four out of ten american families. we look at what's driving the trend. >> woodruff: miles o'brien has the story of advances in facial recognition software. turning the grainiest of photos into information helping police reel in terror suspects. >> we're still blown away on how it works. this actually fit the boston suspect. so that was huge. >> ifill: we continue our series of conversations on immigration reform. tonight, ray suarez talks with two law enforcement officials about the challenges of securing the u.s.-mexico border. >> woodruff: and we close with music legend dolly parton and her literacy program that's delivered nearly 50 million free