Sam and Bert

"I didn't do it!" she cried.
"Didn't do what, Samantha?"
The teenage girl continued to pace the floor in front of me, arms crossed, hair frazzled.
"I didn't stab Jaren in the back. It wasn't me. I just remember him, lying on the floor, my hands all bloody from his wound when Casey walked in and..." sobs overtook her. I watched as she slumped to the ground, crumpled really.
"Then who did?" I asked, trying my best to sound concerned. If I could help it, I was going to refrain from seeing that angry "side" of her again.
Silence. But then, "Don't you dare blame Samantha for this!" a somewhat manly voice came from the crumpled figure on the floor. "Don't you dare try saying this was her fault! This wasn't her fault! She wasn't even there!"
"Bert?" I questioned the girl. She had switched personalities.
"It was me," it grumbled from the floor. "It was me! I killed him!" Samantha/Bert stood and glared at me, walking toward me. "And I would do it again. I'll kill you!"