Mayor Jim Schmitt swore Molitor into office.
Molitor takes over for Chief Jim Arts who is retiring from the department at the end of the week in order to take a job as the head of security for the NFL's Tennessee Titans.
Molitor is not a stranger to the Green Bay Police Department. He served in the department for 21 years before retiring last year as the Deputy Chief.
Molitor will serve in this role until the city hires a new chief. The city hopes to have a new chief by early 2013.