DFL Sen. John Harrington will take over the Metropolitan Transit police department in September.
Harrington is the former St. Paul police chief and served as an officer for more than three decades.
He failed to get the DFL endorsement for his re-election bid this spring. He decided not to run in a primary in his heavily Democratic St. Paul district.
The Metro Transit police department has 69 full time and 55 part time officers who are in charge of safety on buses and trains and patrol the transit routes, according to the department.That's about a tenth the size of the St. Paul police department's 600 sworn officers.
Harrington left the St. Paul department in 2010. That same year he applied but was passed over for the police chief job in New Orleans. A few weeks later, he announced he would run for the state Senate.