. >> officer tony jones has worked these tiers for 14 years and he knows what inmates here are capable of. >> they don't work and play well with others. they're the bad guys here at san quentin. >> a modern prison would have solid doors to protect officers during feeding. but here, the cell fronts are open, allowing inmates the opportunity to assault officers in, perhaps, the most unsavory way possible. >> the absolute worst thing that could happen to you is to have that gassing, is what we call it, that mixture of feces and urine, sometimes fermented for days until it stews into something so grotesque you can't mention it. and that is thrown on the officer through the bars. a lot of these guys are infected with hepatitis b, hiv, and many other diseases. i'd rather be punched. i'd rather be kicked. i'd rather be stabbed than to be gassed like i was back in '92. >> incredible as it may seem, officers at san quentin say that there's an attempted assault on their lives almost every day. >> they look for vulnerable spots. they look for times when you do let your guard down. >> this is deat