"Mister Cactus"

Some people who crossed paths with Luigi Mangione throughout his life say he was kind and had a promising future. How did Brian Thompson's shooter change in the lead-up to his arrest?

Subscribe to 20/20 True Crime+ for ad-free listening, early access to new series, exclusive bonus content, and hundreds of episodes from the 20/20 true crime vault. Visit apple.co/2020truecrime to subscribe now. 

Learn more about your ad choices. Visit podcastchoices.com/adchoices