The changes include the resignations of five board members and the agency's former executive director, now a prison official, after a state inquiry, The Boston Globe reported.
Woburn officer John "Jack" Maguire died in a shootout with Domenic Cinelli after Cinelli attempted to rob a Kohl's department store on the day after Christmas, the report said.
Cinelli had been serving three concurrent sentences of 15 years to life before being paroled in 2008. The killing sparked outrage from the public, political leaders, police and the Massachusetts Chiefs of Police Association, the Globe said.
"After this review, I cannot say that the Parole Board or parole office did all they could to ensure public safety," Patrick said at a Statehouse news conference.
The governor said he was also firing several other parole office staff members, including the chief of the field services office, the field office supervisor and the parole officer in charge of the paroled convict's supervision.
"As I said to (Maguire's widow) when we spoke on the phone just a moment ago, none of this is going to bring Jack back ... but what we have done and what we must do is all we can to regain the public's confidence in a part of the criminal justice system which is vital to a successful criminal justice program," The Boston Herald quoted Patrick telling reporters.