Of fictional crime scene investigators over the years, applying science, experience in moxie, to track down bad guys from clues they leave behind. Our guest today, Paul holtz, is the real thing. He spent a career investigating crimes in California, specializing in cold cases. He played a critical role in identifying one of the most notorious serial predators in American history. The so called Golden State killer, who is admitted to committing 13 murders and 50 rapes in the 1970s and 80s. In a new book holds rights about that case and others and about the day to today work of examining gruesome crime scenes analyzing evidence and speaking to survivors of horrific crimes and relatives of those who didn't survive. He also writes about the emotional toll the work takes. He's experienced nightmares, panic attacks, and marital issues and says he's used plenty of bourbon to self Medicaid. Since retiring from government work in 2018, he's continued to assist investigators and families as a private citizen. And he's become a celebrated figure in the true crime world. He has appeared in the TV series America most wanted and the DNA of murder with Paul holes, and he co hosted a podcast called the murder squad. This fall he'll be co hosting a new podcast with Kate Winkler Dawson about historic crimes its titled buried bones. His new book is unmasked. My life solving America's cold cases. Paul holtz, welcome to fresh air. Thank you for having me. You know, I think we should begin by just telling our listeners that we are going to be talking about some horrific crimes on the show today, and while we won't be giving graphic descriptions of crimes or crime scenes, we will be talking about cases that involve murders and sexual assaults, so it may not be appropriate for all listeners. Paula want to start with a scene that's kind of at the end of the story of this quest for the Golden State killer. And this is at a point when you and other investigators have identified the guy you think is going to be him, a 72 year old guy named Joe Deangelo. You're nearing retirement from government service. And you do an unusual thing you take a visit to his house when he has so far had had no contact with investigators. Tell us why you went, what happened? Well, after 24 years of pursuing this Golden State killer, utilizing new technology, this genetic genealogy technology about a week prior I had been made aware that this Joseph Deangelo was possibly related to the Golden State killer, and after investigating him for a week, and realizing I was going to be retiring the following week, I decided he was a prime suspect, and every time I had a prime suspect in this case, I have to go see where are they living? What are they driving? What is the neighborhood they're living in like? And so on a Monday, I drove up to Citrus Heights, California, which is in the Sacramento area, and parked in front of his house. His car was in the driveway, I knew he was home. But I've been here with prime suspects before, was he really the guy.