dreaming about killing people

I have had several dreams,all different, but they all have the same theme : I have killed several people, cut their bodies into smaller pieces, and hidden them/need to hide them, but in the dream I have no memory of ever doing such a thing nor the inclination. The first of these dreams, I was on the brick patio in my back yard, and after lifting one up, I found the decomposing remains of a childhood friend whom I have not seen in 2 years. I tell my mother, and she very calmly tells me I need to go tell the girl's mother. I find her in an older, lower middle class neighborhood that I recognize in the dream as also being the neighborhood of one of my current best friends(?). In another more recent dream, I discover a black trash bag full of the white powder-covered heads of my murder victims (once again, with no memory of committing the act) and running off to find a place to hide them (in a dumpster at a landfill, apparently). In the first dream, I am horrified at the discovery of the remains, but the second time, I just skip away to dispose of the trash bag. I know I have had another dream with similar events, but i do not remember the details. I am a female high school student.