Real Nightmare

It was 11 O'clock, and I had just arrived back in my dorm from my long shift at Applebee's. My feet were still screaming as I walked over to my bed. They let out a squeal of joy once I finally slipped my shoes off. It felt so amazing to lay down. My roommate was surprisingly sound asleep. I didn't want to bother her so I grabbed my headphones and covered up as I prepared myself to watch a few episodes of psyche on my laptop before I went to bed. It was now 12:01 am and I hadn't seen or heard any noise come from my roommate, which was extremely odd since her snores were louder than the screech of a wild boar. I slowly slid out of my bed and ever so quietly crept over to check on her. I placed my fingers on her neck. There was still a pulse, good she is a live. I didn't think anymore of it, and decided I was extremely tired so I went to bed.
It was now 10:00 am and my roommate still hadn't moved from the same position she was in last night.  She never can sleep past nine so I couldn't figure out what the deal was. I walked over to wake her up because she had class in ten minutes, but it didn't take more than the quick touch to her arm for me to realize the horrifying truth, she was dead.
I started screaming and took of running down the hall to get our RA. I couldn't even begin to describe to her what was going on so I pulled her down to my room and forced myself to show her. She frantically started dialing 911 in an attempt to get help of any sort. Confusion, panic, and chaos had set in.  
After a few hours of sitting in our RA's room and constant questioning from the police, they told me she must have died while I was at work, her legal death time was 10:49 pm.  I just stared at them and said nothing. How could that be? There isn't any way that that could be possible. I felt her pulse at 12:01. I know I did.
I stared at the investigator and with a deep breath I told him that.
He looked at me with a little worry in his eyes and spoke the words to me I will never be able to forget as long as I live, "That pulse you felt wasn't hers. It was her killers."

Bri