Mip Alcohol & Drugs: MIP, MIC, Intoxication

On Saturday (Feb. 2) I was at a birthday party of a guy that turned 21. I had been in the back room of his house talking to some of the girls there when a cop came through the house. They were looking for two girls in blue shirts that had run from him he asked me to go outside and talk to him (I was wearing a black turtleneck). I proceeded outside and the officer asked me who the girl was in the blue shirt outside. I told him I hadn't been outside and I didn't know. He then asked how many drinks I had and said none. He did the follow the pen test but when I asked for a breathalizer he didn't have one to give me. He asked me again how many drinks I had and told him I had one beer earlier that night. He wrote me an MIP and told us later that if he had gone back into the house that he could guarentee that 75% of the people at the party we also get mip's but he said that they would go but if they were called out again they would write everyone else up. My question is how do I get an MIP when he walked through the house with all the minors and only I get the mip?