Further revision of Thriller plot

Our group had created a rough cut of our Thriller and felt having three characters was too confusing for an opening as there wasn't enough time available to make it clear. Therefore we have changed it to two characters and created more of a focus on our murderer also. Our current plot is:

1. Sam (homeless man) is walking to where he will settle for the night
2. Cut to Norma (murderer) who is crossing out a picture of her previous murder victim and circling a picture of Sam (suggesting he is her next victim)
3. Cut to Sam who is sitting
4. Cut to Norma who is preparing for murder
5. Cut to Norma with the weapon in her hand implying she has murdered Sam

Our cliffhanger is the ambiguity of whether Sam is dead or not.