There is no single profile for a serial or mass murderer, but those who are caught often paint a chilling portrait in jailhouse confessions and media interviews. Experts caution that in many cases these ramblings can only be taken with a grain of salt. The killers may simply be repeating something they read, or in the case of Henry Lee Lucas, confessing to crimes they didn't even commit. Others give us an open window into the mind of the criminally insane.
Click on the pictures above to find out what some past mass murderers had to say
Sources: CBSNews.com research, The Associated Press