(AP) Newtown’s police department will review its response to last year’s shooting at Sandy Hook Elementary School, according to the police chief, who said a by the lead investigator showed his officers acted properly.report released this week

The summary report by State’s Attorney Stephen Sedensky III said that nearly six minutes passed between the arrival of the first officer outside the school and the time officers entered the building, but it said police were operating under the belief there may have been more than one shooter.

The report said the lone gunman, Adam Lanza, killed himself about a minute after the first officer arrived at the school.

Police Chief Michael Kehoe said his officers had to make sure several unidentified people encountered outside the school did not pose a threat to police or others.

“You have to have a practical understanding of a response to an active shooter situation,’’ Chief Kehoe said. “Officers have to balance the tactical considerations for engaging the suspect ... or more lives could be in danger.’’

Lanza killed 20 children and six women inside the school on the morning of December 14, 2012. He also killed his mother inside their Newtown home before driving to the elementary school.

Chief Kehoe said his department will begin its review after receiving the complete state police report on the massacre. Such reviews of major incidents help police departments improve response and planning.

The state police are in the process of redacting personal information from the thousands of pages in their evidence file so that they can be released publicly. The Connecticut Division of Criminal Justice said the redactions were expected to be completed by the anniversary of 12/14.

State Police Spokesman Lt. J. Paul Vance said on Wednesday, November 27, he could not say when the completed report would be released.