Detective Matthew Hutchison, who has been a Sunnyvale detective and Department of Safety (DPS) Officer for almost 20 years, appeared on “20/20: Badass Detective,” which premiered on Jan. 9, 2026, on ABC. The episode dives into how Hutchison solved the 1982 murder of 15-year-old Karen Stitt from Palo Alto and the 1979 stabbing of 18-year-old Estella Mena, who was a high-school student working part-time as a security guard.
“I grew up in Sunnyvale,” Hutchison said. “My stepfather worked for DPS, so when I went off to college, I knew this was a career field I wanted to go into, and I wanted to come back to Sunnyvale to work for the community where I grew up. I started to work for public safety. I really like the appeal of the challenge of putting these cases together.”
Since 1950, Sunnyvale has been one of the few cities in America where its police force is fully integrated with its fire departments. This means that Public Safety officers are trained as EMTs, police officers and firefighters.
“When you’re trained in police, fire and EMS, you tend to look at calls or chaotic scenes differently,” Hutchison said in an email. “I can volunteer for sex cases, I can volunteer for cold cases, and so that’s what I did. I wanted to be as busy as I could.” Hutchison spent many years investigating various cases. One specific case would be the homicide of Karen Stitt in 1982. While solving this case, he faced immense doubt from bystanders.
“Each case has its own unique lessons,” Hutchison said. “I was told throughout the entire process, ‘it’s impossible, move on to something else.’ ‘You’re not going to solve this.’ And the lesson that it taught me is no one can tell you what you’re capable of, only you can decide that. So don’t let them be right. Refuse to give up. Refuse to quit.”
Standard DNA testing is used frequently in the cases Hutchison investigates. The majority of cold cases solved by him were solved by using DNA comparison methods. There are two main approaches, the first of which is direct comparison. This is used when there is a known suspect. Database comparison, the second option, is employed when no suspect is known. The database contains DNA profiles of known offenders. The police can look for a one-to-one match between evidence and a profile in the system.
An alternate method for DNA testing is Genetic Genealogy. This is used when there is no match found in the CODIS system. In one instance, family trees of the victims are used to narrow down potential suspects. This was used in the Karen Stitt case.
“I want to live a life that matters outside of my immediate circle of influence,” Hutchison said. “Growing up in Sunnyvale and getting to work in the city also helps me feel connected to the community. I want people in the community growing up today to have the same positive experiences and memories. I’m invested in the city that gave me so much growing up.”
