He's prosecuted some of the worst criminals in Snohomish County history. But after 32 years, Prosecutor Mark Roe has decided to retire but is confident he's leaving the office in good hands.

"It would be much more difficult for me to step away, some people might say in the prime of my life. I'm a mere 59 despite my youthful appearance," Roe laughed during an interview Wednesday.

Few politicians speak as candidly as Roe. His humor helps balance decades of handling tough criminals cases.

"There was one where the little 7-year-old girl looked just like my daughter. And she didn't want to go into the courtroom," remembered Roe. "We put an incredible amount of burden on little children to try those kinds of cases. She pulled against me and she started to tear up and then so did I."

WATCH: Snohomish County Prosecutor Mark Roe describes his toughest cases

The 45-year-old man sitting beside Roe says he shares that same passion. Deputy Prosecutor Adam Cornell, who is running unopposed in the general election, will likely take the reins to lead the office next year.

"This is a job, whether you're a deputy prosecutor or whether you're in Mark's spot, where every single day you get out of bed, you get to ask yourself one question: What is the right thing to do?" said Cornell.

He might sound more like a politician, but Cornell has the chops to back it up. His biggest and most formative case was prosecuting the Mukilteo shootings of 2016.

It's one of the reasons he, as a Democrat, believes in the death penalty since it helped convince the killer, Allen Ivanov, to plead guilty.

"It has to be used very sparingly and absolute certainty of a defendant's guilt," Cornell said.

Cornell's personal background makes his professional success remarkable.

"I entered the foster care system at age 5," said Cornell. "My mom gave me and my three younger siblings up when I was 8 years old. I bounced around from foster home to foster home and tried to find someone to adopt me. I was adopted by a single man at [age] 14, which brought me to the Woodinville area. And shortly before my high school graduation, my father committed suicide. So I've often joked I've been an orphan twice in my life."

WATCH: Deputy Prosecutor Adam Cornell on his foster care upbringing

Roe recalled a conversation between the two of them when Cornell was considering running for state office.

"He's asking my advice and I said, 'Adam, what do you want to do? Because I'll tell you when you do things that other people want you to do, sometimes you're happy.' And he blew me away. He said, 'I want your job.'"

Roe said the recent passing of his mother and aunt and a brief health scare last fall convinced him to retire and spend more time with his wife and kids.

How will the tenured prosecutor feel about leaving it all behind?

"I am completely comfortable," said Roe. "I am proud, not only of what I'm handing over but who I'm handing it over to."

WATCH: How Adam Cornell decided to run for Snohomish County prosecutor