State Police Lieutenant Brian Tully is retiring. 

Tully oversaw the controversial murder investigation in Karen Read's case.  His retirement went into effect on Wednesday, April 8th. 

Previously, Tully commanded the State Police detective unit assigned to the Norfolk County District Attorney's Office.  He was responsible for leading investigations into the deaths of Sandra Birchmore and Read's boyfriend,Boston Police Officer John O'Keefe, in two unrelated cases.