Screaming or howling

The beginning of this dream stemmed from real life, where a friend and I were waiting outside of another friend's house in a car. It was dark outside as it was well beyond 9 PM. All of a sudden, another car pulled up on the other side of the street, but still a bit out of sight. It sat there for a moment doing absolutely nothing and my friend and I got scared. That is until the person checked their mail and promptly drove off -_-; So the dream begins in much of the same way, with the same friend and I in our other friend's neighborhood at night. The difference is that we are walking down the street instead of waiting in a vehicle. As we are walking, I get the strange feeling that something is behind us. On cue, my friend says "Do not look, but somebody is following us I think" and I attempt to catch a glimpse of this person from the corner of my eye and without alerting him or her. The person is shrouded in shadows so I have no idea who he or she is or what they even look like. I turn around and focus on hurrying away without looking too suspicious. But then I get that hair-raising feeling and I know without looking that this stranger is running up behind me. I can feel him on my back and I tense as I see my friend's face morphing in horror. He looks as if he is seen the most horrific thing ever, or as if he can see my life ending before his eyes. The person grabs me in a choke hold from behind. Before I can even react or fend him off, he plunges a knife into my lower back. Fear and sheer panic are flooding through me. I do not even get the chance to scream as he brings the knife around to my throat and jerks it across cleanly, slitting my throat. At that point I do not know if I died in the dream or not because I woke up right after it was over.