Journalist Charlie Scudder investigates the worst serial killer in Dallas history ... In 2016, healthy, active women began to drop dead in Dallas's most exclusive senior living communities and their own homes. Because of their age and where they lived, officials assumed that heart attacks, strokes and other natural causes were to blame. It wasn't until years later, after a woman survived and told police she'd been attacked by a man who tried to smother her with a pillow, that police realized what was actually happening. One of Texas's most prolific serial killers had gone completely undetected. Why were officials so quick to brush aside the deaths as natural? How did the killer use the cracks of a broken system to target some of society's most vulnerable people? And how can we be sure it doesn't happen again?