What Drives A Teen To Kill A Friend? (VIDEO)

In light of recent headlines about teens stabbing to death their one-time friends, Dr. Phil takes a closer look at what could drive an adolescent to kill, and especially why they might murder their own friend.

When Karen Severson was a teen, she and her friends lured 17-year-old Missy — whom they accused of being promiscuous, possibly with their own boyfriends — to a spot in the woods. Then, Missy's hands were tied behind her back, her "friends" chopped off her hair with a knife, Karen pushed her toward a creek, and ultimately, she was murdered. Karen spent 23.5 years in prison for her role in the murder, but still lives every day of her life with the guilt that she turned on her friend and participated in her death.

Dr. Phil asks Karen, "How were you so morally corrupt that this was OK with you at the time ... What was wrong with you that you were that broken?"

Karen explains in the video above, "I was full of anger, hatred, bitterness, resentment. I had an identity crisis growing up. There were a lot of contributing factors in my life ... We were mean girls, we were bullies, and bullies are pack animals. When one started, we fueled the fire to the next."

This episode of Dr. Phil airs Wednesday. Click here to see where you can watch.