. >> when i got on scene, zach and the other -- the officer on scene was talking to matthew riehl. it was fairly calm at that point. >> why don't you come out? you mind if i come in and talk to you, sir? is he on anything? does he have any mental disabilities? >> no. >> i'm going to get your name and i'm going to get out of here, ok? >> hang on. [ shouting ] >> we're here because we want to make sure you're ok. are you ok? >> i'm fine. >> what's your first name? >> matthew. >> zach. good to meet you. >> zach's approach to everything was level headed and calm. >> how was it for you guys? >> we knew the roommate was going to work and going back to his are bedroom. >> two hours later, what happens? >> we get a call. from what we get, matthew rie g was involved. >> he was nonsensical. >> when zach and i arrived at the scene s. zach knocks on the door. an argument ensues from inside the apartment. >> he open the door but been hee does that, what happens? >> ok, open up the door, man, we want to talk to you. >> the way he was talking, he wasn't talking as an authority figure at that poin