ROMANS: The NFL is introducing a new test to evaluate whether a player has been hit too hard to return to the game. Here's why. According to a recent study, at least 100 NFL players suffer concussions within one season. And there are still some concerns about what may have led former Chicago Bear Dave Duerson to kill himself last month. Duerson was part of that famous 1985 Super Bowl team, and he later became a successful businessman and radio host. He shot himself in the chest because he said in text messages that he wanted his brain to be studied for signs of brain damage for the many hits he took on the football field. Chief medical correspondent Dr. Sanjay Gupta has more on what these tests can and can't determine.</s>DR. SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT: Hi, Christine. One thing I want to point out is there have been various sideline exams for some time, but this is a new exam. It is supposed to ensure consistency across all the --</s>ROMANS: All right, we lost that segment from Dr. Sanjay Gupta about concussion tests and what they can and can't show. But, again, it's a very passionate and sad story, really, after the suicide of Duerson just recently -- shooting himself in the chest so that he could preserve his brain so that it could be studied. We'll get back to that Sanjay Gupta segment in just a moment. We're just -- we're just getting word now of hundreds of arrests targeting gangs and drug traffickers across the country. Homeland Security Correspondent Jeanne Meserve joins us live now with more on that. Hi, Jeanne.
NFL Develops New Sideline Tests