LEWISTON – Several staff changes are under way at the police department, where a reorganization includes a newly created rank.

Six patrol officers have been promoted to corporal, a rank created to provide mentoring for new officers as well as additional supervision on street patrol.

Meanwhile, the head of the department’s Criminal Investigation Division has retired after more than two decades on the force.

Wallace “Butch” Pratt, a 24-year-member of the police force retired at the end of the year. Pratt started as a patrol officer and worked his way up through the ranks. For years, he served as the department spokesman before being named commander of CID.

Before he retired, Pratt was also the supervisor of the department’s Internal Affairs Unit, leading investigations into claims against the police force.

The responsibility of the criminal investigations division now falls to Roger Landry, who was promoted from the rank of sergeant to lieutenant.

Landry, an 18-year veteran of the police force, has served in many capacities since becoming a Lewiston police officer. Over the years, he served with the Special Enforcement Team, Maine Drug Enforcement Agency and most recently as a sergeant with CID.

Detective Adam Higgins, a former agent with the Violent Crimes Task Force, has been promoted from detective to sergeant.

Higgins, who joined the force in early 1990, was a patrol officer until 2000 when he was promoted to the rank of detective with the department’s Youth and Family Services Division.

Scot Bradeen has been promoted from patrol to detective. He has served for 12 years in law enforcement, beginning as a patrol officer with the Sabattus Police Department.

In Lewiston, Bradeen has served as a bicycle patrol officer, field training officer, the department’s training coordinator and administrator of the Computer Systems Network.

Bradeen is currently assigned to the Maine Computer Crimes Task Force where he works as a forensic examiner.

The officers promoted to the new rank of corporal are:

• Jeffrey Parshall, a 20-year veteran of the police force who has worked as a field training officer and firearms instructor. Parshall also worked as an investigator on the department’s Selective Enforcement Team;

• Jeffrey Baril, a 14-year member of the force and a Gulf War veteran;

• Raymond Roberts, a 10-year member of the police force and an Emergency Vehicle Operations Course instructor;

• Timothy Darnell, a 10-year member of the force and a Drug Awareness and Resistance Education officer in local schools;

• Dawn Rancourt, an eight-year member of the force who has served as a domestic violence coordinator, a program she initiated at the police department. Rancourt was a police dispatcher before joining the force;

• Kevin Cramp, a six-year member of the force who has served as a field training officer. A U.S. Marine, Cramp was a sergeant with the Mechanic Falls Police Department before joining the force in Lewiston.