Playing a corpse isn't easy, but Hannah Sarrouy, who played a dead girl in Catching Killers, is now a master of the "dead face."

The Night Stalker investigation was blown wide open when - for the first time ever - a laser was used to illuminate latent fingerprints.

When BTK started killing, using DNA evidence wasn't the norm. But 20 years later, tiny traces of DNA left on his first victims could be enough to bring him to justice.

With Michael Swango in custody for fraud, it's up to the scientists to figure out how he killed his patients - before his sentence is up and he gets another chance to escape.