umass dartmouth. investigators out there and they were out there combing the woods, looking for any evidence of any explosives testing, wondering if the tsarnaev brothers could have been testing their bombs thought to make sure that they worked before they brought them here to the marathon route. so far, we haven't gotten word they found anything but do know they are certainly combing that area. >> katy tur on the ground for us in boston. president obama talked about immigration reform during his weekly address from the road. >> this bill is a compromise, which means nobody got everything they wanted, including me but largely consistent with the principles i have laid out from the beginning. these are all common sense steps that the majority of americans support. so there's no reason immigration reform can't become reality this year. back in the united states, the nra is holding its annual convention this weekend in houston. executive director chris cox had some harsh words for gun advocates, like president obama, and new york city mayor michael bloomberg, who cox says exploits