***SPOILERS*** Significance of the scenes at the end?

I enjoyed this, but I can be a little dense when it comes to the weird/metaphorical scenes in movies like this. What is your take on the blood/gun shot suicide scenes at the end? What comment are they making on the lives of the characters?

I also had some difficulty making out what was actually happening as I watched it on youtube in bad quality. Was the screaming girl (who I could hear but not see) being attacked or even killed by the group?