Chaemin Jung joined Lee & Ko in 2021 as a partner after serving more than 16 years with the Korean National Police Agency. His last position of responsibility was the Head of Security Crime Analysis Division of National Office of Investigation, which is an organization newly launched as an affiliated institution of the National Police Agency.

He is currently a partner at Lee & Ko's Criminal Defense Team and specializes in criminal defense work with particular focus on police investigation affairs. While serving as an active police officer, he has handled intelligence, financial, and cyber crime investigations. He was also responsible for violent crimes unit and has handled cases relating to organized crimes, drugs and serious accidents while serving as a frontline officer at the police agencies in Seoul and Gyeonggi Province. In his last position as the head of the Security Crime Analysis Division of the National Office of Investigation, he gained hands-on experiences in public security cases, industrial technology leaks, military defense corruption investigations, and other national policy investigation cases.