dr. mckee had read dr.search, but she wanted to see for herself. >> we dissect and section his brain, do a whole series of microscopic slides, look at it with all sorts of different stains for different things, and then come to a conclusion about what the diagnosis is. >> narrator: what she saw was that tell-tale protein tau. >> this is a 45-year-old with terrific disease. i mean, he had florid disease. he has tau in all these regions of his brain. >> narrator: dr. mckee had examined thousands of brains but the location of the damage from cte was different. >> i remember my feeling. i was scared. i was really scared. it really was a turning point. it was a new understanding that, "hey, this might be bigger than we think." >> narrator: dr. mckee soon had three brains, all with cte but rather than just publish in scientific journals chris nowinski was determined to get the word out. >> nowinski, who is not a scientist, says, "there are people getting hit here. if we speak up now, we may be able to, if not sav